I want to know if a Holy life is possible here on this earth. I don't mean perfect, but Holy, which I believe means that a person has repented from all their sins and they don't commit them ever again. I understand that even if I ask God for forgiveness that's not repenting, it's after I have left the sin and haven't done it again that I'm forgiven. Is a sinless life possible here on this earth?
Obviously God thinks holiness is possible in this world, because he demands it. “Sanctify yourselves therefore, and be ye holy: for I am the LORD your God.” (Leviticus 20:7) “But as he which hath called you is holy, so be ye holy in all manner of conversation; Because it is written, Be ye holy; for I am holy.” (1 Peter 1:15-16) Paul thought it was possible to be holy because he frequently refers to Christians as holy (saints). (1 Corinthians 16:1; 2 Corinthians 1:1; Ephesians 1:1; Philippians 1:1; 4:22; and many others)
Holiness is always associated with sanctification, which means being set apart. It is not perfection. It is, as you say, having your sins forgiven and being set apart from the world. It does not necessarily mean that we don’t sin, but that we don’t intend to sin. Paul argued this point in Romans 7. John adds that we sin even if we are set apart and walking in the light (1 John 1:7), but says that we are continually cleansed from sin if we are trying to live God’s way.
God doesn’t say that he forgives us only if we never again commit the sin that he is forgiving. That would mean that God doesn’t forgive us until we die, because that is the only way to be sure we never did that sin again. Peter told those in Jerusalem on Pentecost that they would be forgiven initially as soon as they were immersed/baptized (Acts 2:38). In Colossians 1:14 Paul says “we have redemption through his blood, the forgiveness of sins.” It is not something we will receive if we never sin a particular sin again, but something we now have.
Holiness, then, is not living a sinless life, but being set apart for a purpose. We are set apart in living a new life (Romans 6). “But ye are a chosen generation, a royal priesthood, an holy nation, a peculiar people; that ye should shew forth the praises of him who hath called you out of darkness into his marvellous light.” (1 Peter 2:9)