‘… who forgives all your sins…’ Psalm 103.3
God does not sweep your sins under a carpet or brush them off as if they never happened. He forgives them, and he has paid the price for them so they can never be put back upon you. God is not selective about which sins he forgives; Jesus paid for them all. It is more a question of which sins you are willing to let go of.
Forgiving yourself is one of the hardest things to do, and it is so easy to continue to carry the burden of sin even though Jesus has totally paid for it.
If you still feel burdened about things in your past, try this exercise. Draw an outline of a cross on a sheet of paper. Within the outline write down the particular sins you feel burdened by. In writing down these words, you are transferring your sin from yourself to the cross. Now destroy the piece of paper: rip it up, throw it away, burn it – anything to demonstrate that those sins have been removed from you. Jesus has taken them away.