If we pray to Jesus, he should know our hearts, and he forgives everyone who truly repents.
And He does! But Jesus also instituted the Sacrament of Confession when He said,
As the Father has sent me, even so I send you.” And when he had said this, he breathed on them, and said to them, “Receive the Holy Spirit. If you forgive the sins of any, they are forgiven; if you retain the sins of any, they are retained.” -John 20:21-23
Why do we need a priest to tell us our sins are forgiven and to give us a penance?
Keep in mind, it is not the priest as himself who forgives sins, but rather the priest
In persona Christi. This means the priest has no power of his own, but it is Christ, through the priest, who forgives us. Jesus is the only one who can forgive us of our sins.
Remember, Jesus is God and therefore knows us better than anyone. I think He instituted the Sacrament of Reconciliation (Confession) knowing full well the total psychology of the human being. If you sin, tell Jesus to forgive you, sin again, etc., I think it’s very hard to break the habit of sin. By making that resolution, to actually tell someone how you have offended God, I think you are much less likely to want to commit that sin again. When you go to Confession, imagine you’re at the foot of Calvary, with Jesus on the cross, because that’s the whole reason your able to be forgiven.
What if I know myself better than him and want to create my own penance?
The penance doesn’t forgive you of your sins. The moment the priest says the words of absolution, your sins are forgiven. The penance is meant to restore what was lost. It begins to repair the soul from the damage that was done to it by the sin and disposes your spirit to again be open to God’s love. Imagine you break your leg. Then you go to the doctor and he fixes it. Well, now you have to go to physical therapy. When the doctor fixed your leg, that’s like Jesus forgiving you. But the physical therapy is the penance.
Also, what types of sins should we confess to a priest? Every lie we told or pens we stole from work? Or only if we committed adultery, or stole $1 million.
It is only required that you confess mortal sins. These are sins that destroy charity within a person. They can only be done consciously. There are three criteria for a sin to be a mortal sin (from the Catholic Catechism, para. 1857):
For a sin to be mortal , three conditions must together be met: “Mortal sin is sin whose object is grave matter and which is also committed with full knowledge and deliberate consent.”
But to add, it is good that we confess
mortal and venial sins because when we confess a sin, we are actually provided a special grace to stop committing that particular sin.
I hope this helps!
God Bless!