Believe in the light (pisteuete eis to phōs). That is, “believe in me as the Messiah” (Joh 8:12; Joh 9:5).
That ye may become sons of light (hina huioi phōtos genēsthe). Purpose clause with hina and second aorist subject of ginomai, to become. They were not “sons of light,” a Hebrew idiom (cf. Joh 17:12; Luk 16:8 with the contrast), an idiom used by Paul in 1Th 5:5; Eph 5:8. It is equivalent to “enlightened men” (Bernard) and Jesus called his disciples the light of the world (Mat 5:14).
Hid himself from them (ekrubē ap' autōn). Second aorist passive indicative of kruptō, late form (in lxx) for old ekruphē, “was hidden from them,” as in Joh 8:59. This part of Joh 12:36 begins a new paragraph.