1 John 3:6
 No one who abides in him keeps on sinning; no one who keeps on sinning has either seen him or known him. (ESV)
One of the greatest hindrances to people placing their faith in Jesus Christ is the fact that they have encountered people who claim to be Christians, yet live a lifestyle no different than the world around them. Have you ever met anyone who has embraced certain sinful behaviors and embraced them as their lifestyle, even claiming that sinful lifestyle as their identity? John has strong words for that person. This person has never known God. They are not Christians
I love how John describes the habitual sinner as one who has never seen or known God. This speaks of relationship. Christianity is not a club. It is a relationship with God. If you do not have a relationship with God, you are not a Christian. You can go to a Christian church. You can pay tithes. You can donate time to missions works and good causes. But if you do not have a relationship you are not a Christian.
The fact is, Christians are lovers of Christ. And as you grow in your love for Christ you begin to love the things he loves (righteousness) and hate the things he hates (sin). That is why a person who keeps on sinning proves that they truly do not love Christ. And if they do not love Christ they truly do not know him. A genuine relationship with God changes our attitude toward sin.
"If Christ has died for me, ungodly as I am, without strength as I am, then I cannot live in sin any longer, but must arouse myself to love and serve Him who has redeemed me."
- Charles Spurgeon
You and I both struggle with sin. Is your sin a lifestyle? Habitual? You need salvation! If you know the Savior, draw close to him and find victory over your sin. He loves you.