Hebrews 6:4
6:4 For it is impossible in the case of those who have once been enlightened, tasted the heavenly gift, become partakers of the Holy Spirit,
Hebrews 11:6
11:6 Now without faith it is impossible to please him, for the one who approaches God must believe that he exists and that he rewards those who seek him.
Hebrews 6:18
6:18 so that we who have found refuge in him 1 may find strong encouragement to hold fast to the hope set before us through two unchangeable things, since it is impossible for God to lie.
1 tn Grk “have taken refuge”; the basis of that refuge is implied in the preceding verse.