He will convince the world concerning...righteousness...because I go to the Father. John 16:10, R.S.V.
Jesus has always worn two hats, as it were. But, then, doesn't any competent mediator? But with Jesus, both hats are worn for the benefit of the same party.
In the situation of an estranged couple, a good counselor will try to bring reconciliation by getting each party to see the other's viewpoint. To do this he will mediate between the two, standing in the place of first and then the other. By this gentle substitutionary shifting, the counselor allows the offended parties to work through their animosities and fears without having to deal directly with each other.
In our estrangement from God, Jesus is the mediator. God has taken the first step in our direction by stating that He is holding nothing against us. Paul wrote, "Our message is that God was making all mankind his friends through Christ. God did not keep an account of their sins, and he has given us the message which tells how he makes them his friends" (2 Cor. 5:19, T.E.V.).
God doesn't need to have His mind changed concerning us! In every way possible He lets us know that He accepts us. Why, then, do we need Jesus to mediate for us? The answer is simple: we feel the need to "test the waters" in our return to God. So Jesus dons the hat of mankind and goes into the Father's presence, not to win over the Father but so that we can be convinced of the Father's response.
The other hat Jesus wears is divinity. Coming to us, He portrays our God as warm, forgiving, accepting, and extremely desirous of reestablishing friendship with us "He who has seen me," Jesus told His disciples, "has seen the Father" (John 14:9, R.S.V.). So He is God's gracious substitute, even as He is ours.
Both hats are for our benefit!. And the ultimate statement of God's acceptance of us is to have Jesus, our Substitute, living in God's presence today. We can be totally convinced that our relationship has been set right because Jesus has gone to the Father and has been accepted as us! No wonder Jesus said later, referring to the time He would once again be with us, "In that day you will ask nothing of me" (chap. 16:23, R.S.V.). It will no longer be necessary; we will be one with the Father, just as He is!