Dear brothers and sisters in Christ,
St. Paul writes to Timothy: "there is one God, and there is one mediator between God and men, the man Christ Jesus" (1 Timothy 2:5).
In the way Moses pleaded the case of the Israelites before Yahweh on Mt. Sinai, appealing to the everlasting covenant God had made with Abraham, so Jesus Christ pleads your case, and the exhibit A for your mediator is his sacrifice on the cross, which is credited to you through Baptism.
But with God, one is often not enough.
Baptism would have been enough, but God also gives the preached Word (holy Absolution and the Sermon, for example) and the Lord's Supper. Any one of these alone brings all the gifts of God in Christ: forgiveness, life and salvation. But God doesn't give any one of these alone.
So too, having Christ as a mediator would have been enough, but God hasn't given Christ only. St. Paul tells us also that "the Spirit helps us in our weakness. For we do not know what to pray for as we ought, but the Spirit himself intercedes for us with groanings too deep for words" (Romans 8:26).
Indeed, if it was comforting to know that Jesus mediates for you, and pleads your case with the Father, home much more is it to know that God has given another, who intercedes for you, and delivers your prayers to the Father.
Faith is always ready to receive whatever God will give. And sometimes, God decides that one gift is not enough. Amen.