Every Christian is given the righteousness of God in Christ, to replace the flesh unrighteousness. You seem to say you repent of some sins, but hang on to others, always remaining with sin, so call yourself a sinner. Upon true repentance a person is at least for a while sin-free until sinning again, else it is isn't true the Lord forgives upon repenting. But he does do that, enabling us to increasingly live by faith, as all the Just ought to do.
A major part of salvation is that by the help of the Spirit we should stop thinking ourselves as sinners, but "I am righteous in Christ." When righteous our first impression is to do the words of Christ. Reading the 4 gospels you won't see much theology from Jesus. He taught people how to enter into the Kingdom, and what to do there, how to live pleasing to God. He was very practical. There epistles carry on with theology helping us to catch up to the full mind of Christ. That's why it all comes into us, two helpers, the Spirit and the word, even our very faith.
Having the righteousness of Christ in me doesn't mean I no longer sin at all. It makes me be quick to repent, and quicker to not enter into a sin situation. As fruit of the spirit grows in me, I exercise wisdom, which is often just clamping my mouth shut instead of sinning with my tongue.
Galatians 2:15-21 (KJV)
[SUP]15 [/SUP] We who are Jews by nature, and not sinners of the Gentiles,
[SUP]16 [/SUP] Knowing that a man is not justified by the works of the law, but by the faith of Jesus Christ, even we have believed in Jesus Christ, that we might be justified by the faith of Christ, and not by the works of the law: for by the works of the law shall no flesh be justified.
[SUP]17 [/SUP] But if, while we seek to be justified by Christ, we ourselves also are found sinners, is therefore Christ the minister of sin? God forbid.
[SUP]18 [/SUP] For if I build again the things which I destroyed, I make myself a transgressor.
[SUP]19 [/SUP] For I through the law am dead to the law, that I might live unto God.
[SUP]20 [/SUP] I am crucified with Christ: nevertheless I live; yet not I, but Christ liveth in me: and the life which I now live in the flesh I live by the faith of the Son of God, who loved me, and gave himself for me.
[SUP]21 [/SUP] I do not frustrate the grace of God: for if righteousness come by the law, then Christ is dead in vain.