Word Origin: Derived from μέσος (mesos), meaning "middle" or "between."

Corresponding Greek / Hebrew Entries: While there is no direct Hebrew equivalent for "mesités," the concept of a mediator can be related to the role of a priest (כֹּהֵן, kohen) or an intercessor (פָּגַע, paga).

Usage: The term "mesités" refers to a mediator, one who intervenes between two parties to restore peace, make a covenant, or ratify an agreement. In the New Testament, it is primarily used to describe Jesus Christ as the mediator between God and humanity, highlighting His role in reconciling sinful humans to a holy God through His sacrificial death and resurrection.

Cultural and Historical Background: In ancient Greek culture, a mediator was often a neutral party who facilitated negotiations or resolved disputes. In the context of the New Testament, the concept of a mediator is deeply rooted in the Jewish understanding of a priestly role, where the priest acted as an intermediary between God and the people. Jesus, as the ultimate High Priest, fulfills this role perfectly, bridging the gap caused by sin.

-- Strong's Lexicon

Jesus is our mediator, according to Paul:

For there is one God, and there is one mediator between God and men, the man Christ Jesus -- 1 Timothy 2:5 (ESV)

The translators' choice to refer to Jesus as "one mediator between God and men" is appropriate because Jesus made it possible for us to access God by his sacrifice which redeemed us from our sin. This covenant make forgiveness possible and allow us to have a relationship with God. Therefore, Jesus is considered a mediator.

For if the blood of goats and bulls, and the sprinkling of defiled persons with the ashes of a heifer, sanctify for the purification of the flesh, how much more will the blood of Christ, who through the eternal Spirit offered himself without blemish to God, purify our conscience from dead works to serve the living God. Therefore he is the mediator of a new covenant, so that those who are called may receive the promised eternal inheritance, since a death has occurred that redeems them from the transgressions committed under the first covenant. -- Hebrews 9:13-15 (ESV)