A.T. Robertson Commentary Hebrews 11:6

"And without faith it is impossible to be well-pleasing [unto him]; for he that cometh to God must believe that he is, and [that] he is a rewarder of them that seek after him." — Hebrews 11:6 (ASV)

Impossible (αδυνατον). Strong word as in 6:4,18. See Ro 8:8 for same idea with αρεσα (αρεσκω, Galatians 1:10).

Must believe (πιστευσα δε). Moral necessity to have faith (trust, πιστευω). This is true in business also (banks, for instance).

That he is (οτ εστιν). The very existence of God is a matter of intelligent faith (Romans 1:19ff.) So that men are left without excuse.

He is a rewarder (μισθαποδοτης γινετα). Rather, "becomes a rewarder" (present middle indicative of γινομα, not of ειμ). Only N.T. example of μισθαποδοτης, late and rare double compound (one papyrus example, from μισθος (reward) and αποδιδωμ (to pay back) like μισθαποδοσια (10:35; 11:26).

Seek after (εκζητουσιν). That seek out God.