Hebrews 6:1

6:1 Therefore we must progress beyond the elementary instructions about Christ and move on to maturity, not laying this foundation again: repentance from dead works and faith in God,

Hebrews 6:4-6

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, 6:5 tasted the good word of God and the miracles of the coming age, 6:6 and then have committed apostasy, to renew them again to repentance, since they are crucifying the Son of God for themselves all over again and holding him up to contempt.