How do we know that Christ is the only mediator between God and man?

According to 1 Timothy 2:5, 'For there is one God and one mediator between God and men, the man Christ Jesus.' This exclusive role of Christ as the mediator emphasizes that no human being, including Mary or the apostles, serves in this capacity. His unique position derives from His dual nature as fully God and fully man, allowing Him to bridge the gap created by sin. The efficacy of His mediation is rooted in His perfect sacrifice and the righteousness He offers to those He reconciles to the Father. This is foundational to sovereign grace theology, affirming that all access to God is solely granted through Christ, rejecting any notion of human intermediaries.