Concerning the mediator
The doctrine of the Mediator, which is intimately connected with the glory of God and our comfort, must be carefully considered for the following reasons: 1. That we may acknowledge and magnify the mercy of God, in that he has given his Son to be our Mediator, and to be made a sacrifice for our sins. 2. That we may know God to be just, in as much as he would not, out of his clemency, pardon sin; but was so greatly displeased therewith that he would not remit it, except satisfaction were made by the death of his Son. 3. That we may be assured of eternal life, in having a Mediator who is both willing and able to grant it unto us.
4. Because the doctrine of the Mediator is the foundation, and substance, of the doctrine of the church. 5. On account of heretics, who at all times oppose, with great bitterness, this doctrine; and that, having a proper knowledge of it, we may be able to defend it against all their assaults.
The doctrine of the Mediator seems to belong to the article of justification, because there also the office of the Mediator is explained. But it is one thing to teach what, and what kind of a benefit justification is, and how it is received, which is done when the doctrine of justification is treated of; and it is another thing to show whose benefit it is, and by whom it is bestowed upon us, which properly belongs here.