Our Efforts vs. God's Grace or Our Efforts and God's Grace
One sin against God, especially a mortal sin, is so great that there is no way we can ever make full satisfaction or even come close to fully satisfying our debt. We are dust and God is infinite goodness, love and perfection.
But...just because we can't even come close, doesn't mean we shouldn't do our best to make amends for our sins - to do penance. Not only that, we should never give up in that effort. If we are truly humble and repentant and really desire to heal the damage we have caused, God may at some point take over and elevate all our efforts. He may complete the process for us. God is the great multiplier! He may, in an instant, multiply our good works and desires in a way that will more than satisfy for the harm we have caused. But it seems that most of the time he works gradually to heal us and others from the effects of our sins. It may be that He knows something we don't know: Living a life of penance is a fruitful, joy-filled life for many reasons.
Before we talk about one of the reasons for this, let's answer the following question: Why does God want us to do what we can to make amends for our sins? Didn't he take away the need for that through Jesus' suffering, death and resurrection? The answer is that Jesus' loving sacrifice has more than fully supplied for the eternal punishment for our sins, that is he has saved repentant sinners from hell. But he did not completely take away the temporal punishment (temporary) - the wounds and effects of our sins on ourselves and others in this life. It is his grace that heals these negative effects but this grace is applied through our efforts to do penance for them.
In other words, our efforts are not the source of grace; we cannot save ourselves or others from the effects from our sins. Instead, our efforts are a channel of God's grace. By offering loving acts of penance we are setting ourselves up to be in the position to receive the grace he won for us. Jesus wants us to work along side him in this endeavor because through this effort, we are practicing virtue, and it is by practicing virtue that we are changed and transformed! Practicing virtue helps our souls to become good soil for his leaven (grace) to grow, flourish and elevate us far beyond our own efforts. We see and example of this in the miracles of the multiplication of the five loaves and two fish to feen over 5000 people. Jesus could have created food from nothing but he wanted the apostles to have a part in this miracle. He wanted them to do their best then he did the rest.
This is one of the reasons that Jesus said "If anyone desires to come after me, let him deny himself, and take up his cross, and follow me" (Matthew 16:24).
Lent is a great time to practice penance more intentionally in order to make amends for our sins - one of the most important purposes of Lent. The whole Church is on this journey together and there is strength in numbers. We are in this together. All of us sin and have need of authentic repentance followed up by acts of penance. Jesus is with us in this effort, preceding, accompanying, and following up with his grace - his help and support. Jesus himself said, “Where two or three are gathered in my name, there I am in the midst of them” (Matthew 18:20).
Learn more about temporal punishment and penance here. There are other reasons for carrying our crosses. Learn about some of them here.