{Impossible} (adunaton). Strong word as in  6:4,18 . See
 Ro 8:8  for same idea with aresai (aresk(935c),  Ga 1:10 ). {Must
believe} (pisteusai dei). Moral necessity to have faith (trust,
pisteu(935c)). This is true in business also (banks, for instance).
{That he is} (hoti estin). The very existence of God is a
matter of intelligent faith ( Ro 1:19ff. ) So that men are left
without excuse. {He is a rewarder} (misthapodot(8873) ginetai).
Rather, "becomes a rewarder" (present middle indicative of
ginomai, not of eimi). Only N.T. example of misthapodot(8873),
late and rare double compound (one papyrus example, from
misthos (reward) and apodid(936d)i (to pay back) like
misthapodosia ( 10:35  11:26 ). {Seek after} (ekz(8874)ousin).
That seek out God.