The nature of confession

My concept of confession is probably similar to yours: Admission of sin. It conjures a darkened room with a single light hanging over a table, and two detectives looking menacingly at a suspect. "We know you did it," one of them sneers. "Confess now and we'll go easy on you."

To some degree, confession as admission of wrongdoing is true. But that's not all it means when it comes to the Christian faith. It is considerably more nuanced and rich than simply admitting you're wrong. The word "confess" or "confession" is found 18 times in the NT. Here are some examples:

1Jn. 1:9 If we confess our sins, he is faithful and just and will forgive us our sins and purify us from all unrighteousness.      

He. 13:15 Through Jesus, therefore, let us continually offer to God a sacrifice of praise — the fruit of lips that confess his name.      

1Ti. 6:13 In the sight of God, who gives life to everything, and of Christ Jesus, who while testifying before Pontius Pilate made the good confession...

Ro. 10:9-10 That if you confess with your mouth, “Jesus is Lord,” and believe in your heart that God raised him from the dead, you will be saved. For it is with your heart that you believe and are justified, and it is with your mouth that you confess and are saved.

Jn. 12:42 Yet at the same time many even among the leaders believed in him. But because of the Pharisees they would not confess their faith for fear they would be put out of the synagogue...

We can see that confession is much more broad than the admission of sin. It also is the admission of truth as related to God. Jesus made the good confession, that is, He told the truth about God. Jesus confessed, "I am."

Taking a look at the Greek word for "confession," (homologéō), we find it is a compound word. The first part of the word is "from 3674 /homoú, 'together,'" and the second part is "3004 /légō, 'speak to a conclusion.'" That is, "to voice the same conclusion, i.e. agree ('confess'); to profess (confess) because in full agreement; to align with (endorse)." 

Confession, then, is to become one with or speak agreement with something. At its root, "one voice." God has said X, I speak my full agreement.

So what is it we speak with full agreement about?

All have sinned. (Ro. 3:23)  

If we claim we have not sinned, we are liars (1Jn. 1:10)

There is only one way to God (Jn. 14:6)

We must not indulge in the sinful nature (Ga. 5:13)

We are no longer condemned (Ro. 8:1)

We have been released from the law (Ro. 7:6)            

We have passed from death to life (1Jn. 3:14)              

We are His workmanship (Ep. 2:10.)                

We are a holy priesthood (1Pe. 2:5)            

We have the mind of Christ (1Co. 2:16)

We are co-heirs with Christ (Ro. 8:17)

God has spoken, we must agree (confess) that not only is His Word true, but that we also come into conformity with it. We admit His truth, and adhere to it.

This is the essence of the Lord's Prayer: "Thy kingdom come, Thy will be done, on earth as it is in heaven." This is the Grand Agreement, agreement with the Word of the Lord and His purpose on earth, that all who claim the name of Jesus would confess Him.