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.

Hebrews 6:10

6:10 For God is not unjust so as to forget your work and the love you have demonstrated for his name, in having served and continuing to serve the saints.