Hebrews 6

¹Therefore let us leave the elementary doctrine of Christ and go on to maturity, not laying again a foundation of repentance from dead works and of faith toward God, ²and of instruction about washings, the laying on of hands, the resurrection of the dead, and eternal judgment. ³And this we will do if God permits. ⁴For it is impossible, in the case of those who have once been enlightened, who have tasted the heavenly gift, and have shared in the Holy Spirit, ⁵and have tasted the goodness of the word of God and the powers of the age to come, ⁶and then have fallen away, to restore them again to repentance, since they are crucifying once again the Son of God to their own harm and holding him up to contempt. ⁷For land that has drunk the rain that often falls on it, and produces a crop useful to those for whose sake it is cultivated, receives a blessing from God. ⁸But if it bears thorns and thistles, it is worthless and near to being cursed, and its end is to be burned.
⁹Though we speak in this way, yet in your case, beloved, we feel sure of better things—things that belong to salvation. ¹⁰For God is not unjust so as to overlook your work and the love that you have shown for his name in serving the saints, as you still do. ¹¹And we desire each one of you to show the same earnestness to have the full assurance of hope until the end, ¹²so that you may not be sluggish, but imitators of those who through faith and patience inherit the promises.

¹³For when God made a promise to Abraham, since he had no one greater by whom to swear, he swore by himself, ¹⁴saying, “Surely I will bless you and multiply you.” ¹⁵And thus Abraham, having patiently waited, obtained the promise. ¹⁶For people swear by something greater than themselves, and in all their disputes an oath is final for confirmation. ¹⁷So when God desired to show more convincingly to the heirs of the promise the unchangeable character of his purpose, he guaranteed it with an oath, ¹⁸so that by two unchangeable things, in which it is impossible for God to lie, we who have fled for refuge might have strong encouragement to hold fast to the hope set before us. ¹⁹We have this as a sure and steadfast anchor of the soul, a hope that enters into the inner place behind the curtain, ²⁰where Jesus has gone as a forerunner on our behalf, having become a high priest forever after the order of Melchizedek.

source