- - -It's absurd for the Lord to grant man the privilege of working with Him to achieve His ends? Sure, He could do all things on His own, but He wills that we cooperate with Him, so as to elevate man above all creatures and grant him the dignity that comes with doing the work of the Lord. We see this throughout Scripture:
Mark 16:20 And they went forth and preached everywhere, while the Lord worked with them and confirmed the message by the signs that attended it. Amen.
Rom 8:28 We know that in everything God works for good with those who love him, who are called according to his purpose.
1 Cor 3:9 For we are God's fellow workers; you are God's field, God's building.
2 Cor 6:1 Working together with him, then, we entreat you not to accept the grace of God in vain.
We do the Lord's work in many ways. When husband and wife procreate they participate in the Lord's work of Creation. When we lead people to Christ, we participate in the Lord's work of Salvation. Paul in particular, as well as James and Jude, speak rather explicitly about this:
Rom 11:13-14 Now I am speaking to you Gentiles. Inasmuch then as I am an apostle to the Gentiles, I magnify my ministry 14 in order to make my fellow Jews jealous, and thus save some of them.
1 Cor 7:16 Wife, how do you know whether you will save your husband? Husband, how do you know whether you will save your wife?
1 Cor 9:22 To the weak I became weak, that I might win the weak. I have become all things to all men, that I might by all means save some.
1 Tim 4:16 Take heed to yourself and to your teaching; hold to that, for by so doing you will save both yourself and your hearers.
Jas 5:20 let him know that whoever brings back a sinner from the error of his way will save his soul from death and will cover a multitude of sins.
Jude 1:22-23 And convince some, who doubt; 23 save some, by snatching them out of the fire; on some have mercy with fear, hating even the garment spotted by the flesh.
Seeing all this, there is simply nothing absurd about the Lord choosing to give man a part in His work of Forgiveness. The precedent of human involvement in the Lord's work has surely been established, and with this we have the very words of Jesus in which he grants the Church the power to forgive sins (John 20:21-23).
I hope that helps. For more information on the sacrament of Confession, go here.