2Ti 2:19 Nevertheless the solid foundation of God stands, having this seal: "The Lord knows those who are His," and, "Let everyone who names the name of Christ depart from iniquity."
It should be the Christian experience that sin is reduced. a) from our choosing to abandon it, and b) God's Spirit working in us.
1 Jn 3:3-10 And everyone who has this hope in Him purifies himself, just as He is pure. Whoever commits sin also commits lawlessness, and sin is lawlessness. And you know that He was manifested to take away our sins, and in Him there is no sin. Whoever abides in Him does not sin. Whoever sins has neither seen Him nor known Him. Little children, let no one deceive you. He who practices righteousness is righteous, just as He is righteous. He who sins is of the devil, for the devil has sinned from the beginning. For this purpose the Son of God was manifested, that He might destroy the works of the devil. Whoever has been born of God does not sin, for His seed remains in him; and he cannot sin, because he has been born of God. In this the children of God and the children of the devil are manifest: Whoever does not practice righteousness is not of God, nor is he who does not love his brother.
The Bible is quite clear that the one who goes on sinning is not saved. Although this is not perfect righteousness, it is definitely a boost of sorts.
Gal 2:21 I do not set aside the grace of God; for if righteousness comes through the law, then Christ died in vain."
As for my experience, let's take my relationship with my wife. I love my wife. I choose to not look at other women, be they real or the online or paper variety. I try to treat her well and allow her to just do life. I help her with the housework, as often as she wishes it. But as for sin, I may occasionally disagree with her, and get forceful rather than have an accommodating nature. So although I do my best to love my wife, I still sin against her from time to time, by being disagreeable in nature. A Christian should have no "Big" sins, and the small ones should happen infrequently. Yet it is God's Holy Spirit that keeps us on track. That is why Jesus asks us to spend time in God's presence.
Mark 14:38 Watch and pray, lest you enter into temptation. The spirit indeed is willing, but the flesh is weak."
This does not mean a Christian who has committed a "Big" sin is no longer saved, but rather they should seek genuine repentance, turning from that sin, they should try to not do it again.