Hebrews 6:4-6 NIV

[4] It is impossible for those who have once been enlightened, who have tasted the heavenly gift, who have shared in the Holy Spirit, [5] who have tasted the goodness of the word of God and the powers of the coming age [6] and who have fallen away, to be brought back to repentance. To their loss they are crucifying the Son of God all over again and subjecting him to public disgrace.