For it is impossible in the case of those who have once been enlightened, tasted the heavenly gift, become partakers of the Holy Spirit,
tasted the good word of God and the miracles of the coming age,
and then have fallen away, 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.
Matt 12:31–32 “Therefore I say to you, every sin and blasphemy will be forgiven men, but the blasphemy against the Spirit will not be forgiven men. Anyone who speaks a word against the Son of Man, it will be forgiven him; but whoever speaks against the Holy Spirit, it will not be forgiven him, either in this age or in the age to come.
Luke 12:10 “And anyone who speaks a word against the Son of Man, it will be forgiven him; but to him who blasphemes against the Holy Spirit, it will not be forgiven.”
Can you be a Christian and fall away?
My sheep hear my voice, and I know them, and they follow me.
I give them eternal life, and they will never perish, and no one will snatch them out of my hand.
My Father, who has given them to me, is greater than all, and no one is able to snatch them out of the Father’s hand.
For I am sure that neither death nor life, nor angels nor rulers, nor things present nor things to come, nor powers,
nor height nor depth, nor anything else in all creation, will be able to separate us from the love of God in Christ Jesus our Lord.
For the ground that has soaked up the rain that frequently falls on it and yields useful vegetation for those who tend it receives a blessing from God.
But if it produces thorns and thistles, it is useless and about to be cursed; its fate is to be burned.
But: Hebrews 6:9–12
But in your case, dear friends, even though we speak like this, we are convinced of better things relating to your salvation.
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
But we passionately want each of you to demonstrate the same eagerness for the fulfilment of your hope until the end,
so that you may not be sluggish, but imitators of those who through faith and perseverance inherit the promises.
Hebrews does not want to leave us sad and anxious
Don’t get stuck in introspection, but look at Jesus