"Jesus replied, 'No one who puts his hand to the plow and looks back is fit for service in the kingdom of God.'" Luke 9:62
"For we know that our old self was crucified with him so that the body of sin might be done away with, that we should no longer be slaves to sin--" Romans 6:6
"Do not conform any longer to the pattern of this world, but be transformed by the renewing of your mind." Romans 12:2
"Therefore, if anyone is in Christ, he is a new creation; the old has gone, the new has come!" 2 Corinthians 5:17
"But one thing I do: forgetting what is behind and straining toward what is ahead, I press on toward the goal to win the prize for which God has called me heavenward in Christ Jesus." Philippians 3:13-14
"...since you have taken off your old self with its practices and have put on the new self, which is being renewed in knowledge in the image of its Creator." Colossians 3:10
"For he (Abraham) was looking forward to the city with foundations, whose architect and builder is God." Hebrews 11:10 (Abraham in parenthesis added)
"Let us fix our eyes on Jesus, the author and perfecter of our faith..." Hebrews 12:2
Jesus came to earth not so that we could re-live, turn inside out and go over and over again with a magnifying glass every past mistake, memory, incurred hurt, relationship, holiday, birthday and missed opportunity! And I don’t mean to minimize how horrid and incredulous some of those experiences have been. But Jesus came to reconcile us (2 Corinthians 5:18-19). He came to give us unconditional, unmerited favor (2 Corinthians 6:2) and love from God (1 John 4:10) and to instill in us His peace, trust and hope (John 14:27 and 16:33). Jesus provides the way out of ourselves (and our past) through post conversion works of gratitude (John 7:18, James 2:26).
This isn't to say we shouldn't or can't learn from the past. It does mean that a life with Christ demands we don't stay there. I think Colossians 3:5 explains it best when it says "Put to death, therefore, whatever belongs to your earthly nature: sexual immorality, impurity, lust, evil desires and greed, which is idolatry." In essence, put a stop to whatever is coming between us and God.
Sadly, it is often our past that comes between us and God. The compulsion to look back, repeatedly reliving and retelling everything bad that ever happened in our lives, without ever getting past it, becomes an idol. We ignore the hand of Jesus Christ waiting to take ours and pull us out of the mire. It's so much easier, more dramatic or less scary to stagnate in our problems, sin, and past hurts. Maybe it's all we know or ever have known. But to cling to the past (which includes sin we've brought with us from the past) is to ignore God's call to offer our entire being--past, present and future--to Him.
Edna Mode saw no point in going backwards and gave Mr. Incredible a brand new suit. Jesus wants us to go forward too. We can choose to continue living in or trying to obsessively make sense of the past, or we can start over, learning from and living with Jesus Christ. Will we let go our grip on bygone years--and the sin (ours and other's) we've carried with us--and accept today under His Lordship?