1 Timothy 2:5

For there is one God--God's unity in essence and purpose is a proof of His comprehending all His human children alike (created in His image) in His offer of grace (compare the same argument from His unity, Rom 3:30; Gal 3:20); therefore all are to be prayed for. Ti1 2:4 is proved from Ti1 2:5; Ti1 2:1, from Ti1 2:4. The one God is common to all (Isa 45:22; Act 17:26). The one Mediator is mediator between God and all men potentially (Rom 3:29; Eph 4:5-6; Heb 8:6; Heb 9:15; Heb 12:24). They who have not this one God by one Mediator, have none: literally, a "go-between." The Greek order is not "and one mediator," but "one mediator also between . . . While God will have all men to be saved by knowing God and the Mediator, there is a legitimate, holy order in the exercise of that will wherewith men ought to receive it. All mankind constitute, as it were, ONE MAN before God [BENGEL]. the man--rather "man," absolutely and genetically: not a mere individual man: the Second Head of humanity, representing and embodying in Himself the whole human race and nature. There is no "the" in the Greek. This epithet is thus the strongest corroboration of his argument, namely, that Christ's mediation affects the whole race, since there is but the one Mediator, designed as the Representative Man for all men alike (compare Rom 5:15; Co1 8:6; Co2 5:19; Col 2:14).

— Jamieson-Fausset-Brown Commentary (public domain)