A mediator is one who intervenes between two others in a dispute for the purpose of reconciling their differences.
Specifically, Jesus acts as our mediator with God the Father, by paying for the penalty of our wrong doing (that is, sin), thereby reconciling us to God.
His role of mediator continues with his ongoing intercession for his followers (1 John 2:1 and Hebrews 7:25).
Key verse about Mediator: For there is one God and one mediator between God and mankind, the man Christ Jesus (1 Timothy 2:5, NIV)
A lifelong student of the Bible, Peter DeHaan, PhD, wrote the 1,000-page website ABibleADay.com to encourage people to explore the Bible. His main blog and many books urge Christians to push past the status quo and reconsider how they practice their faith in every area of their lives.