I want to take two separate ideas and tie them together. We’ll see how this works out. “If we confess our sins He is faithful and just to forgive us our sins and cleans us from all injustice,” I John 1:9. This idea is pretty simple and I don’t think you need me to explain it to you. I do want to highlight one thing, though, it requires something of us. We can’t just assume that God is going to forgive us, we have to own our mistakes, and then He is faithful to forgive us. God first requires something from us.
This is also stated as a commandment, “And when (anyone) is guilty of one of these, he must confess that in which he sinned.” (Leviticus 5:5) This verse is in the context of one certain kind of sin, but it can be understood to apply to all sins, based on R. Yishmael’s principle of “A general rule based on one verse” (introduction to Sifra). In other words, the Torah only mentions it in this one place, but this is just an example that shows us the general rule.
But the next verse, Leviticus 5:6 commands the person who confesses to then bring a sacrifice to the Temple. How can we do this without a Temple? Psalm 141:2 sets the precedent, “May my prayer be accepted as incense before You, the raising of my hands as the afternoon sacrifice.” This is why the sages began the practice of reciting the sacrifices every morning (Babylonian Talmud, Taanit 27b). In that way, our prayer takes the place of the sacrifice.
R. Yeshua also talks about confessing our sins “Our Father in Heaven, may Your Name be holy … and forgive us our sins, as we have forgiven our debtors…” (Matthew 6:9&12). In the Eighteen Benedictions (Shemoneh Esrei), which is prayed three times every day, there are two prayers in which we refer to God as “Our father.” These are the prayer of repentence, and the prayer for forgiveness. When we admit to our sins and try to correct our behavior God, like a good and loving father, is faithful to forgive us. As Leviticus 5 shows us, this should be accompanied with a sign (like a sacrifice) that we intend to change our behavior, and so we read the sacrifices, and we say the Eighteen Benedictions, which are also take the place of the sacrifices (Babylonian Talmud, Berachot 26b)
These prayers were instituted to fulfill the commandments of confession and atonement, but this is just one reason for our prayers. The rabbis can give us a lot more reasons for faithfully following the traditions of daily prayer.