{One God} (heis theos). Regular Pauline argument for a
universal gospel ( Ga 3:20  Ro 3:30  Eph 4:6 ). {One mediator}
(heis mesit(8873)). Late word (Polybius, Philo) from mesos
(middle), a middle man. In N.T. only here,  Ga 3:20  Heb 8:6  9:15  12:24 . {Between God and men} (	heou kai anthr(9370)(936e)).
Ablative case (though objective genitive may explain it) after
mesit(8873) (notion of separation) as in  Ro 10:12  Heb 5:14 .
{Himself man} (anthr(9370)os). No "himself" (autos) in the Greek.