One Mediator of All? (1 Timothy 2:1-7; LD 18; BC Article 26)

The claim that there is one mediator that we have in Christ seems like a poor arrangement.  We think that it stands to reason that to have more eggs in more baskets provides for us additional security.  So, why would we wantto rest in the one God-Man who resides in the glory of heaven? So, why is it good that we have one mediator?  What does it mean that He is the mediator of all?  Why would we be content with such a mediator?