I think sometimes our past can be a pitfall for so many of us Christians and non-Christians. For the non-Christian it can be the very reason that keeps them from coming to Christ, "How could God love someone like me". "I have sinned too much". Or for the Christian it can hold them back from God's full potential, "I am not good enough"!
I have shared before about how God forgets our sin when we ask for forgiveness. I wish we could do the same. But since we can not...we must do our best to "forget those things behind us" with God's help.
"Reaching forward to those things which are ahead" is what God is calling us to do. I have begun to realize that when I focus on the reaching the forgetting becomes easier. Why is that? It's because I am now using all my energy in moving forward. I have transferred the energy from sulking to working. God is calling us to do more, be more. When we do that and work hard at it, we are too busy with God's business than sitting in the corner saying, "Whoa is me". We need to understand that God forgives, He wants to forgive, He longs to forgive and He sent his son to die so He could forgive. He went to great lengths for us to show us how much He loves us...who are we to say, "He can't forgive me". We hold our own selves back.
So reach forward for the goal the prize is His calling in Christ Jesus. When we give all that we are He can give us so much more in return.