It depends - If you've never made a commitment to Christ, then you've never had your sins forgiven, and there's only one way to get rid of your guilt...trust Jesus as your Lord and Savior and ask for His forgiveness.

If you're a Christian, then the guilt you're feeling falls into one of two categories:

*TRUE GUILT - The kind that comes after you've done something wrong and have not admitted it to God. Take responsiblity for what you have done, and admit it to God.
"If we confess our sins, He is faithful and just and will forgive us our sins and purify us from all unrighteousness." - 1 John 1:9

*FALSE GUILT - You've confessed your sins to God, but still feel guilty. Well, don't! Once we give it over to God, He takes it away, as far as the east is from the west. Don't be tricked! Know that God loves you and has forgiven you.
"As far as the east is from the west, So far has He removed our sins from us" - Psalms 103:12