“If we confess our sins He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.” 1John 1:9
When we come to Jesus in simple faith and trust Him for our salvation we become “righteous,” or right with God. The gospel isn’t about what I can do for God, but about what God did for me on the cross. “He who knew no sin (Jesus), became sin, in order that we (I) might become the righteousness of God in Him.” (2Corinthians 5:21)
Yet as Christians we are still broken in many ways and that leads to unplanned sins. God’s presence and power are in us and as we walk with Him He is gradually healing us, but it is a process and not an immediate result. Until we’re completely healed (which actually won’t be until heaven!), we’re going to need many new beginnings. God knew this, so He promised to forgive us along the way.
His forgiveness is “just” in His eyes because Jesus already died for those sins. He doesn’t arbitrarily forgive sins just because He loves us; He forgives us when we’re in Christ because the full punishment for sin has already been paid. Because of Jesus, the only sin that can’t be forgiven is the one we are unwilling to confess. (See John 9:41)
Be honest and be humble. Keep short accounts with God and know that He is gradually healing you on the inside, so you won’t have to confess the same things over and over forever. As we’re healed in one area, however, He will start shining His light on another. All we have to do is keep walking in the light (John 1:7) which is another way of saying we simply need to walk with God.