When I talk to other believers about their walk with God, I ask them a few simple (but related) diagnostic questions. I start with something like this, "What was the first and greatest commandment God gave to Israel?" The answer is found in Matthew 22:36-40,
“Teacher, which is the great commandment in the Law?” And He [i.e. Jesus] said to him [i.e. the lawyer/Pharisee who asked the question to test Jesus], “‘You shall love the Lord your God with all your heart, and with all your soul, and with all your mind.’ This is the great and foremost commandment. The second is like it, ‘You shall love your neighbor as yourself.’ On these two commandments depend the whole Law and the Prophets.” [NASB]
The "Law" that is spoken of in this passage is often called the Law of Moses because it was given to Israel through Moses who was chosen to be (and acted as) the mediator of a covenant between Israel and God. God promised to bless Israel if they kept his commands. It was that simple.
Even though the Law of Moses is no longer in effect (having been invalidated and replaced by a New Covenant), those who come to God through Christ under this same New Covenant, are still required to love one another:
A new commandment I give to you, that you love one another, even as I have loved you, that you also love one another.- John 13:34 [NASB]
This is My commandment, that you love one another, just as I have loved you. - John 15:12 [NASB]
This I command you, that you love one another. - John 15:17 [NASB]
Owe nothing to anyone except to love one another; for he who loves his neighbor has fulfilled the law. - Romans 13:8 [NASB]
For you were called to freedom, brethren; only do not turn your freedom into an opportunity for the flesh, but through love serve one another. - Galatians 5:13 [NASB]
Now as to the love of the brethren, you have no need for anyone to write to you, for you yourselves are taught by God to love one another; - 1 Thessalonians 4:9 [NASB]
Since you have in obedience to the truth purified your souls for a sincere love of the brethren, fervently love one another from the heart, - 1 Peter 1:22 [NASB]
Above all, keep fervent in your love for one another, because love covers a multitude of sins. - 1 Peter 4:8 [NASB]
For this is the message which you have heard from the beginning, that we should love one another; - 1 John 3:11 [NASB]
This is His commandment, that we believe in the name of His Son Jesus Christ, and love one another, just as He commanded us. - 1 John 3:23 [NASB]
Jesus not only lived as a Jew under the Mosaic Covenant Laws - He kept them perfectly, which means that He loved the Lord His God with all His heart, soul, mind and strength - continuously. He also loved others in the same way.
Beloved, let us love one another, for love is from God; and everyone who loves is born of God and knows God. - 1 John 4:7 [NASB]
Beloved, if God so loved us, we also ought to love one another. - 1 John 4:11 [NASB]
Now I ask you, lady, not as though I were writing to you a new commandment, but the one which we have had from the beginning, that we love one another. - 2 John 1:5 [NASB]
No Jew ever loved God with all of his or her mind, soul, heart and strength. No Jew - and let's expand that - no person (since the fall) has ever loved God the way we are called to, except Christ.
Becoming a Christian doesn't change you into a sinless being. Christians still have sinful desires, and fall into sin when they aren't actively standing against it. Our default condition remains selfish and self-serving - which is why we are taught by the scriptures not to let these desires rule us, but instead to understand that it is the very source of this proclivity that damned us before God. That proclivity continues to rule over the life we inherited from Adam (what the Apostle Paul describes as our "old man" or "old self" in Romans 6) but that same proclivity cannot reign over the life of Christ we inherited when we were baptized into the life, death, and resurrection of Christ.
We don't typically view ourselves as a person who is simultaneously connected to two lives - the first is the one we have always known - from which all sinful desires are provoked; that sinful life we have inherited from Adam. The second we have received through the Holy spirit - the life of Christ. We experience the life of Christ almost as a second set of desires - but desires which are holy, good, and selfless rather than self-serving, selfish, and sinful. The Apostle Paul makes it clear in Romans 7 that the Christian experiences both sets of desires in the same body, and must choose to obey those desires whose origin lies in our new life in Christ, rather than those which come from our old life - which was put to death in Christ.
How do we overcome those sinful desires which remain?
Every new believer typically starts the same way - they find themselves suddenly sensitive to sin before God, and desire to avoid God's displeasure at their ongoing disobedience, so they begin to cut as much sin out of their life as they can. The rest of their sin, they hide from everyone else, until they can get it under control. But they never get it under control, or if they do, it never remains under their control. In this struggle they wonder what is wrong with them. Maybe their salvation didn't work, or maybe Christianity is all bunk. They feel like they missed something - some piece of the puzzle which when found will unlock their hobbled Christianity, but the months and years go by, and they either give up, or they simply make peace with the sin that remains in their life. They can't seem to get rid of it, so they continue to experience guilt and remorse as a necessary consequence of their unwillingness to repent. Of course they wouldn't describe their unwillingness to repent as unwillingness - they would describe it as an inability...
I recall ministering to a fellow who was fully and thoroughly convinced that he was unable to resist the temptation to view porn on the internet. We were walking, and I remember stopping in mid stride and turning to him and saying, "Do you mean to tell me that if I offered you one million dollars to go a day without viewing porn, you would throw away that million dollars if the temptation hit you before the day was out? Or would you not rather just fight that temptation till the day was up, and get the million dollars?" As you'd expect, he agreed with me that he could find the strength to resist the urge if doing so meant a million dollars in the bank at the end of the day. Obviously he had the strength and power to resist this temptation - he just didn't want to. In this case, another sinful desire (greed) was able to trump the other desire (lust) because it promised him a bigger return.
The reason a lot of Christians struggle against sin, is because they love their sin, and aren't willing to give it up - even for all the riches that fellowship with God in this life here and now promises. They know they ought to love God, but they love their sin more than they love God.
The question is why? How can a Christian love their own self above everything and anyone else? The answer is because that Christian isn't being a Christian, they are continuing in their sin and rebellion against God. Such a Christian is not repenting.
No one can become a Christian apart from repentance. You must repent of your unwillingness to obey God. That means that at some point you surrender your will and life to God, for His command - this you do trusting that God will save you through Christ as the New Covenant promises. Anyone who does that sincerely will be saved in the moment of their sincerity - they will inherit the life of Christ and receive the Holy Spirit who has already been at worth in them making them able (spiritually speaking) to comprehend these truths which provoked the same required repentance that was granted to them by God. No sinner is able to repent of their rebellion against God's rule, because that would be righteous, and there are none who are righteous, as the bible teaches. God as an act of divine grace, grants the believer the ability to trust in the promises of God, and grants the believer the ability to repent of their rebellion against God's rule, and fully surrender themselves to God's rule.
Yet once that happens, the old sinful desires are not eradicated - they persist. This has confused many a new convert - if I am saved, why do I still desire to rebel against God's rule (or said another way, why do I still want to sin)? Now begins the work of sanctification. It works exactly the same way our justification (i.e. our salvation) worked: we are enlightened and empowered (by the life of Christ within us through the Holy Spirit who provokes us) to obey those desires which arise from the life of Christ, and to deny those desires which rise up from our old life/self.
Insofar as we humble ourselves before God, we obey - and that includes our obedience to the greatest command: the command to love one another - even as Christ loved us.
If my understanding of "love" is cultural rather than biblical - I'm going to take that command and think, I love everyone in my church - meaning I feel some sort of bond of affection with everyone there. I like being with them, some more than others, but by and large I "love" them - I even say so now and again, "I love you guys".
But that kind of love, doesn't serve anyone like Christ served the church - giving himself entirely over in service to others. How many of us put the needs of others ahead of our own needs? How many of us are are willing to love others as long as there is no perceived cost to doing so (whether in resources like money or items, or investing ourselves in the life and support of others - i.e. in physically being there for others)?
You see the love that we show for one another puts us daily in the lives of one another. Is there someone in the body who is weak, those acting in true, biblical love won't wait for a posse to form before acting being there to strengthen them. They won't put their weekend plans above the needs of the church - and let me say this, every church is needy, even the healthy ones.
God expresses Himself in the church most visually, and with the greatest conviction - when the church members live their lives in the service of others in the church. Our gifts - our spiritual gifts - are given that we might function within the church in God's strength rather than our own. But we won't do that if we continue to live for ourselves.
I don't see many healthy churches today - instead I see a lot of churches meeting on Sundays, and ignoring each other the rest of the week. In many churches the only people routinely exercising their gifts are the pastors. Listen, the unwashed masses should see God in the church on Sunday - not just in the preaching, but (and perhaps more especially) in the lives of the believers invested fully in the lives of other believers. They should see the church every time they come to visit a Christian, or speak with one.
How are you serving your brothers and sisters in Christ believer? List for yourself what you plan to do this week, and ask yourself who you're serving - your congregation or yourself?
If the greatest commandment given to the believers is to love one another (meaning to serve one another in love - to strengthen each other, to look out for each other, to physically be there in the lives of other believers) how are you doing?
We have this mindset in the flesh, not to give anyone more than they deserve. We walk past the drunkard lying passed out in a pool of his own filth on the sidewalk because we've judged that it was his sin that got him there, and stopping to check on his welfare will be fruitless and best and possibly dangerous. Plus, who wants to make friends with a drunkard? If they want our help, let them meet us half way.
But that isn't how God helped us is it?
Did I deserve that grace that found me in my sin, revealed the truth to me, and enlightened my life that I could repent and believe? All I had to commend me to Christ was a life given entirely over to sin - nothing I did brought me half way, or part way, or in any way closer to God. He met me in my sin, and pulled me out of it. I didn't deserve that. That is what love looks like - someone serving someone else who doesn't deserve to be served at all, and certainly doesn't deserve to be served with the kind of earnest full-hearted service (i.e. love) we are called to serve one another with.
Recognize therefore that to wait until someone deserve your help (love), wouldn't be love by the time you gave it. Love - the love we are called to - doesn't seek it's own, it gets no payback whatsoever. It is not an affection that we foster for the needy - it is not restricted just to people with gregarious hearts and extroverted personalities. Love is for every Christian - love is that selfless service that we give undeserving others because we received the same from Christ when he saved us. It is the living testimony of the live of God in a person - apple trees produce apples. The life of Christ in you produces a life like Christ in you - a life that serves others.
Maybe you didn't count the cost when you came to Christ, because the person or situation that brought you to Christ didn't make the cost clear. But the Christian life is a life of service. Don't let a bad start turn into a bad race, followed by a dismal finish. Take up your cross, believer, and follow Christ today.
If you don't know how to start, talk to God. Share your heart with Him - warts and all. Don't let the sun go down on you today until you've spoken to God about you lack of genuine repentance, and your predisposition to ignoring this greatest of Christian commands.
If you don't know any obedient Christians, then be the first one in your group. Your changed life will affect others positively. God made the church in such a way that we all need other Christians to bring us to our greatest potential. None of us is able to walk the path of sanctification alone - because there will be times when we will need the strength, prayers, and living example of others to testify to us in our moments of weakness and failure. Lacking that, we can only rise to the level of our own strength - and we're all pretty lazy and weak when it comes down to it.
Our obedience to the command to love one another, will result in obedience elsewhere in our walk - for how can we serve the body of Christ effectively, when we're busy serving ourselves?
Think about it.