It is impossible for us to live a sinless life.
Jesus Christ is the only one who could.
He gave his sinless life as a sacrifice so that we might have our sins forgiven.
If we want forgiveness of sins and eternal life in the kingdom of God, we must:
1. Understand and believe the gospel preached by Jesus and his apostles.
2. Repent of our sinful way of life (change the way we live).
3. Be baptised by immersion in water for the forgiveness of past sins.
Acts 2:38 Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins…
Acts 22:16 And now why tarriest thou? arise, and be baptized, and wash away thy sins, calling on the name of the Lord.
4. Live a new life by obeying Christ’s commandments.
Romans 6:4 Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life.
John 15:13 Greater love hath no man than this, that a man lay down his life for his friends. 14 Ye are my friends, if ye do whatsoever I command you.
After baptism we will still sin but if we are making a determined effort to live by Christ’s commandments, our sins will be forgiven by confession in prayer.
1 John 1:7 But if we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus Christ his Son cleanseth us from all sin. 8 If we say that we have no sin, we deceive ourselves, and the truth is not in us. 9 If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.
Hence the Lord’s prayer:
Luke 11:4 And forgive us our sins; for we also forgive every one that is indebted to us.
I hope you find this helpful.