I'm not sure how I got on
Buffalo Regional Right to Life's mailing list, but a recent newsletter contained an Act of Contrition which offers much for meditation. One can sin through malice or through ignorance. Obviously, the sins we commit out of ignorance limit our culpability, but they still offend God's justice. Praying and sacrificing in atonement for those sins, both our own and those of others, can be a response to St. Paul's admonition to "make up what's lacking in the suffering of Christ." (Colossians 1:24)
Obviously, Jesus' sacrifice is perfect so what can possibly be lacking? The answer: our free will decision to join our sufferings to His. He will never force our will, but He invites us to participate in the salvation of the world. If you read
Fr. Collins' description of God's covenantal relationship with us, you know how much God desires our union with Him and with each other. Whenever we sin, we break that covenant and damage both our relationship with God and with the human family. It is good to ponder on that and repent.