Is Practicing Supposed Transubstantiation Falling Away?

CARM.org, while I don't agree with every point that they make--although I agree on the essentials--, makes a point about transubstantiation:

It should be obvious to anyone who believes the word of God, that the Roman Catholic doctrine of transubstantiation is not biblical.  For the reasons listed above, we urge that Roman Catholics recognize that Jesus Christ died once for all and that there is no need to participate in a ritual where His re-sacrifice is practiced.

Finally, because the sacrifice of Christ was once for all, it is sufficient to save us and we do not need to maintain our salvation by our efforts or by our participation in the Lord's supper.  It is not a means of grace that secures our salvation or infuses into us the grace needed that then enables us to maintain our salvation by our works.  Instead, we are made right before God by faith.

That CARM.org didn't reference the following is a little surprising:

Hebrews 6:4-6

New King James Version (NKJV)

⁴ For it is impossible for those who were once enlightened, and have tasted the heavenly gift, and have become partakers of the Holy Spirit, ⁵ and have tasted the good word of God and the powers of the age to come, ⁶ if they fall away,^[a] to renew them again to repentance, since they crucify again for themselves the Son of God, and put Him to an open shame.

Footnotes:

1. Hebrews 6:6 Or and have fallen away

Hebrews 10:26-31

New King James Version (NKJV)

The Just Live by Faith

²⁶ For if we sin willfully after we have received the knowledge of the truth, there no longer remains a sacrifice for sins, ²⁷ but a certain fearful expectation of judgment, and fiery indignation which will devour the adversaries. ²⁸ Anyone who has rejected Moses’ law dies without mercy on the testimony of two or three witnesses. ²⁹ Of how much worse punishment, do you suppose, will he be thought worthy who has trampled the Son of God underfoot, counted the blood of the covenant by which he was sanctified a common thing, and insulted the Spirit of grace? ³⁰ For we know Him who said,“Vengeance is Mine, I will repay,”^[a] says the Lord.^[b] And again, “The Lord will judge His people.”^[c]31 It is a fearful thing to fall into the hands of the living God.

Footnotes:

1. Hebrews 10:30 Deuteronomy 32:35
2. Hebrews 10:30 NU-Text omits says the Lord.
3. Hebrews 10:30 Deuteronomy 32:36

Evangelical and truth-seeking Catholics: please take note and run while you can, or--if you're called to stay and be used to reform the Roman Catholic Church--pray on your calling to help reform the Roman Catholic Church. By the way, I have previously referenced the Yeshuat Yisrael study on Hebrews 6:4-6; and in other words, you will not lose your salvation if you participate and have participated in transubstantiation. But be warned:

⁹ For we are God’s fellow workers; you are God’s field, you are God’s building. ¹⁰ According to the grace of God which was given to me, as a wise master builder I have laid the foundation, and another builds on it. But let each one take heed how he builds on it. ¹¹ For no other foundation can anyone lay than that which is laid, which is Jesus Christ. ¹² Now if anyone builds on this foundation with gold, silver, precious stones, wood, hay, straw, ¹³ each one’s work will become clear; for the Day will declare it, because it will be revealed by fire; and the fire will test each one’s work, of what sort it is.¹⁴ If anyone’s work which he has built on it endures, he will receive a reward. ¹⁵ If anyone’s work is burned, he will suffer loss; but he himself will be saved, yet so as through fire.

Remember, "if we sin willfully after we have received the knowledge of the truth, there no longer remains a sacrifice for sins"; and in supposed transubstantiation, "they crucify again for themselves the Son of God, and put Him to an open shame." If you fall away, you "will suffer loss; but...will be saved, yet so as through fire." But you do not want to fall away.