A.T. Robertson Commentary John 5:38

"And ye have not his word abiding in you: for whom he sent, him ye believe not." — John 5:38 (ASV)

And (κα). "And yet" as in 1:10 and 5:40 below.

His word abiding in you (τον λογον αυτου εν υμιν μενοντα). But God's word had come to them through the centuries by the prophets. For the phrase see 10:35; 15:3; 17:6; 1 John 1:10; 2:14.

Him ye believe not (τουτω υμεις ου πιστευετε). "This one" (τουτω, dative case with πιστευετε) in emphatic relation to preceding "he" (εκεινος, God). Jesus has given them God's word, but they reject both Jesus and God's word (John 14:9).