I was reading At Home with Our Faith today - a little four page newsletter that David's school sends home once a month. Mary Lynn Hendrickson was writing about the importance of forgiveness, especially as it relates to Lent. The whole Lenten / Easter experience is about forgiveness. God loved us so much he sent his only Son to save us from our sins. God is always ready to forgive when we ask for forgiveness. And so should we be ready to forgive others who hurt us. In fact, we say that in the "Our Father" - "Forgive us our trespasses as we forgive those who trespass against us."
Lent is about turning our back on our old ways, the habits that keep us from having the loving relationship with God and others that we should, so that on Easter we can celebrate our new life, our new birth in Christ. We all fail. We all sin. That is part of life here on earth. We can, thanks to Christ, all get a second chance (and a third and a fourth and a fifth, etc.!) to try again.
As Hendrickson points out, however, we must try not to make the same mistake again. We can't go tell God we are sorry while having every intention of doing the same thing tomorrow. Yes, we may trip up and actually make the same mistake the next day, but we can't have planned on doing it. We actually have to try to resist temptation and try to do better.
An "Act of Contrition" is a good thing to add to one's night prayers as you look over the day and tell God you are sorry for the times you screwed up:
"O my God, I am heartily sorry for having offended you, because I dread the loss of heaven and the pains of hell, but most of all because you are all good and deserving of all my love. I firmly resolve, with the help of your grace, to sin no more and to avoid the near occasions of sin. Amen"