Charles Spurgeon Commentary Hebrews 6:4-6

"For as touching those who were once enlightened and tasted of the heavenly gift, and were made partakers of the Holy Spirit, and tasted the good word of God, and the powers of the age to come, and [then] fell away, it is impossible to renew them again unto repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame." — Hebrews 6:4-6 (ASV)

For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost, and have tasted the good word of God, and the powers of the world to come, if they shall fall away,—

Note that Paul does not say, "If they shall fall;" but, "If they shall fall away,"—if the religion which they have professed ceases to have any power over them—then, it shall be impossible—