God decodes what He means when He uses the phrase “untempered morter”. If we examine these chapters carefully with the knowledge and understanding that “no flesh” (nobody) has ever been justified (forgiven/saved) by the works of the law including the Old Testament believers, then we can also see and understand what God’s covenant requirements are for eternal life.
Those requirements are to do justice and judgment by obeying His laws and turning away from sinning. This formula is what governs the gospel of Jesus Christ (confession and repentance) which was also taught and preached to all the Old Testament believers.
But when their leaders taught the opposite for money, God was very angry and called their building practices “untempered morter” because what they built spiritually would never stand (Matthew 7:24 & Luke 6:48). On top of that, God’s righteousness was polluted by them because of their lies and actions (works).
These leaders were saying it was ok to sin by teaching that unrepentant sinners could still have eternal life, “to slay the souls that should not die” (killing the righteous believers who became corrupted by unrepentant sinning) while also promising to “save the souls alive that should not live” (by promising eternal life to the wicked unrepentant sinners).
These scriptures are describing the false doctrine of “Once Saved Always Saved”:
“Because, even because they have seduced My people, saying, Peace; and there was no peace; and one built up a wall, and, lo, others daubed it with UNTEMPERED MORTER: Say unto them which daub it with untempered morter, that it shall fall: there shall be an overflowing shower; and ye, O great hailstones, shall fall; and a stormy wind shall rend it.”
“And will ye pollute Me among My people
for handfuls of barley and for pieces of bread,
TO SLAY THE SOULS
THAT SHOULD NOT DIE,
AND to save the souls alive
THAT SHOULD NOT LIVE,
by your lying to My people that hear your lies?”
“Because with lies ye have made the heart of the righteous sad, whom I have not made sad; and strengthened the hands of the wicked, that he should not return from his wicked way, by promising him life: Therefore ye shall see no more vanity, nor divine divinations: for I will deliver My people out of your hand: and ye shall know that I am the LORD.”
“There is a conspiracy of her prophets in the midst thereof, like a roaring lion ravening the prey; they have DEVOURED souls; they have taken the treasure and precious things; they have made her many widows in the midst thereof. Her priests have violated My law, and have profaned Mine holy things: THEY HAVE PUT NO DIFFERENCE BETWEEN THE HOLY AND PROFANE, neither have they shewed difference between the unclean and the clean, and have hid their eyes from My sabbaths, and I am profaned among them. Her princes in the midst thereof are like wolves ravening the prey, to shed blood, and TO DESTROY SOULS, TO GET DISHONEST GAIN. And her prophets have daubed them with untempered morter, seeing vanity, and divining lies unto them, saying, Thus saith the Lord GOD, when the LORD hath not spoken. The people of the land have used oppression, and exercised robbery, and have vexed the poor and needy: yea, they have oppressed the stranger wrongfully. And I sought for a man among them, that should make up the hedge, and stand in the gap before Me for the land, that I should not destroy it: but I found none. Therefore have I poured out Mine indignation upon them; I have consumed them with the fire of My wrath: their own way have I recompensed upon their heads, saith the Lord GOD.”
“Ye have not gone up into the gaps, neither made up the hedge for the house of Israel TO STAND IN THE BATTLE in the day of the LORD.”
The power of God’s might is truth and righteousness. Justice and judgment is strength, and virtue is power (Luke 8:46).
“Finally, my brethren, be strong in the Lord, AND IN THE POWER OF HIS MIGHT. Put on the whole armour OF GOD, that ye may be able to stand against the wiles of the devil. For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places. Wherefore take unto you the whole armour of God, that ye may be able to withstand in the evil day, and having done all, to stand. Stand therefore, having your loins girt about WITH TRUTH, and having on the breastplate of righteousness; And your feet shod with the preparation of the gospel of peace; Above all, taking the shield of faith, wherewith ye shall be able to quench all the fiery darts of the wicked. And take the helmet of salvation, and the sword of the Spirit, which is the word of God: Praying always with all prayer and supplication in the Spirit, and watching thereunto with all perseverance and supplication for all saints”
“Thy righteousness is an everlasting righteousness,
and Thy LAW is the TRUTH.”
“It is God that girdeth me with STRENGTH,
and maketh my WAY perfect.”
“The LORD hear thee in the day of trouble; the name of the God of Jacob defend thee; SEND THEE HELP FROM THE SANCTUARY, and strengthen thee out of Zion”
“The LORD will give STRENGTH unto His people;
the LORD will bless His people with PEACE.”
(“The way of peace” is the law of God, the gospel of God: “And your feet shod with the preparation of the gospel of peace” Ephesians 6:15.)
“O God, Thou art terrible out of Thy holy places: the God of Israel is He that giveth strength and power unto His people. Blessed be God.”
“I will go in the STRENGTH of the Lord GOD:
I will make mention of Thy RIGHTEOUSNESS,
even of Thine only.”
“Blessed is the man whose strength is in Thee;
in whose heart are THE WAYS of them.”
“Bless the LORD,
ye His angels, that excel in STRENGTH,
THAT DO His commandments,
hearkening unto the voice of His word.”
“For wisdom is a defence, and money is a defence: but the excellency of knowledge is, that wisdom giveth life to them that have it.”