Before salvation a person fulfil the deeds of the flesh deliberately and glory in them but after salvation the same person should only do them involuntarily and if deliberate he is to ask for forgiveness, forsake them and move on
But any christian saying we cannot be perfect is trying to justify himself instead of focusing on God's grace to overcome those weaknesses.
It is true we are imperfect human but what God has given to us is enough to overcome our imperfection. Jesus was made example for us as the bible said he was tempted as we are but did not sin. We shall be tempted too but we should not yield. Jesus almost did in Gesthemane but called himself to order and God strenghtened him
Paul describe one of the effects of being saved as being made alive from dead conscience.
Ephesians 2:1-2 - And you He made alive, who were dead in trespasses
and sins, 2 in which you once walked according to the course of this
world, according to the prince of the power of the air, the spirit who
now works in the sons of disobedience
Before salvation you could do all those deeds of the flesh and brag about them, enjoy the company of bad friends and so on. But after salvation, you become a new person [in heart] and you won't feel comfortable about those things any more.
Unlike before you feel remorseful everytime you do those things. This is because the Spirit of God is now active in you. That's what God is looking at, a broken spirit, a contrite heart, a sober mind. You will still do them but the frequency would reduce day by day.
If after being remorseful you keep doing them over and over, you will go back to your previous state - dead conscience
Romans 8:13 - For if ye live after the flesh, ye shall die...
But if you yield to God's Spirit then you will drop those things.
Romans 8:13 but if ye through the Spirit do mortify (put to death -
NLT) the deeds of the body (Sinful Nature - NLT), ye shall live.
It is very important that we surrender our hearts to the Holy Spirit because it is only through this we can do it. ... Now if any man have not the Spirit of Christ, he is none of his (Romans 8:9)
If you look at the fruit of the Spirit, it is complete opposite of the deeds of flesh. Holy Spirit is very important.
If you LOVE you can't HATE
If you like PEACE there will be no DISCORD-ENVY-JEALOUSY
and one leads to another
And finally,
Luke 7:21 - Not everyone who says to Me, 'Lord, Lord,' will enter the
kingdom of heaven, but he who does the will of My Father who is in
heaven will enter the kingdom of heaven, but he who does the will of My Father who is in
heaven will enter
A christian who justify his sinful habits is not a true christian or may be slipping away
Ephesians 1:3 - Blessed be the God and Father of our Lord Jesus
Christ, who hath blessed us with all spiritual blessings in heavenly
places in Christ
Everything we need to succede as a christian has been provided in christ according to that verse and we have them at our fingertips [The Word, The Spirit, Constant Fellowship with God and much more]