The Law of Moses showed that no man can live a life without sin.
Romans 3:20 Therefore by the deeds of the law there shall no flesh be justified in his sight: for by the law is the knowledge of sin.
Romans 3:23 For all have sinned, and come short of the glory of God;
Romans 5:12 Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned:
For this reason God fathered a son through Mary. Jesus Christ is the only son of Adam who has ever lived a perfect life.
God accepted his perfect life as a sacrifice to take away the sins of those who believe and obey the gospel.
1 John 3:5 And ye know that he was manifested to take away our sins; and in him is no sin.
If we believe the gospel, recognise our sinfulness and repent, we can have our past sins washed away by baptism and begin a new life.
Acts 2:38... Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins...
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.
In this new life we will still sin but we are promised forgiveness if we confess in prayer.
1 John 1:9 If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness. 10 If we say that we have not sinned, we make him a liar, and his word is not in us.
Whilst we remain flesh and blood we cannot live a perfect life.
Righteousness is imputed to us by faith in Jesus Christ.
Romans 4:3 For what saith the scripture? Abraham believed God, and it was counted unto him for righteousness... 23 Now it was not written for his sake alone, that it was imputed to him; 24 But for us also, to whom it shall be imputed, if we believe on him that raised up Jesus our Lord from the dead;
Perfection will not come until Christ returns to raise us from the dead and give us the divine nature.
Philippians 3:20 For our conversation (conduct) is in heaven; from whence also we look for the Saviour, the Lord Jesus Christ:21 Who shall change our vile body, that it may be fashioned like unto his glorious body, according to the working whereby he is able even to subdue all things unto himself.
2 Peter 1:4 Whereby are given unto us exceeding great and precious promises: that by these ye might be partakers of the divine nature, having escaped the corruption that is in the world through lust.
Flesh and blood, being imperfect, cannot inherit the kingdom of God.
1 Corinthians 15:50 Now this I say, brethren, that flesh and blood cannot inherit the kingdom of God; neither doth corruption inherit incorruption... 53 For this corruptible must put on incorruption, and this mortal must put on immortality. 54 So when this corruptible shall have put on incorruption, and this mortal shall have put on immortality, then shall be brought to pass the saying that is written, Death is swallowed up in victory. 55 O death, where is thy sting? O grave, where is thy victory? 56 The sting of death is sin; and the strength of sin is the law. 57 But thanks be to God, which giveth us the victory through our Lord Jesus Christ.
Those who attain to the kingdom of God at the return of Christ will live perfectly on the earth forever.
I hope you have found this helpful.
May God bless you,