All of my religious books push the same things: Jesus is God, the Divine Son, Christianity is the True Faith, but every church under the cross is a false church: every church under the cross leads people to perdition.

If you say that is all wrong, if you insist one or more denominations under the cross lead people to Heaven, well, suppose you are 100% correct. But suppose also that there are hundreds or thousands of denominations under the cross lost in heresy that lead people to perdition.

John 14. 23-26 and Matthew 16.13-19 mean one is a heretic bound for Hell if he says there is no True Church or if he says there are multiple True Churches.

Look at the Roman Catholic Church. Rome either leads people to Heaven or else Rome doesn't lead people to Heaven. Rome is either God's True Church or else Rome isn't God's True Church. The Pope is either a Holy Father or else he is NOT a Holy Father...

Henry Charles Lea wrote in his 'A History of the Inquisition of the Middle Ages' (1922),

'We have only to look upon the atrocities of the criminal law of the Middle Ages to see how pitiless men were in dealing with each other. The wheel, the caldron of boiling oil, burning alive, burying alive, flaying alive, tearing apart with wild horses, were the ordinary expedients by which the criminal jurist sought to deter crime by frightful examples...An Anglo-Saxon law punishes a female slave convicted of theft by making eighty other female slaves each bring three pieces of wood and burn her to death....In the Customs of Arques, granted by the Abbey of St. Bertin in 1231, there is a provision that, if a thief have a concubine who is his accomplice, she is to be buried alive...In France women were customarily burned or buried alive for simple felonies, and Jews were hung by the feet between two savage dogs, while men were boiled to death for coining. In Milan Italian ingenuity exhausted itself in devising deaths of lingering torture for criminals of all descriptions. The Carolina, or criminal code of Charles V., issued in 1530, is a hideous catalogue of blinding, mutilation, tearing with hot pincers, burning alive, and breaking on the wheel...'

1 Corinthians 11. 27-29 says you drink damnation into your soul if you celebrate Holy Communion in an unworthy manner.

For century after century churches gave the bread and the wine to evil kings, evil nobles, evil slavemasters...

2 Thess 2 deals with the Antichrist, strong delusion AND A FALLING AWAY.

WHERE IS THERE EVIDENCE OF A FALLING AWAY?

Gibbon narrates: 'Ninety thousand Jews were compelled to receive the sacrament of baptism; the fortunes of the obstinate infidels were confiscated; their bodies were tortured...Their frequent relapses provoked one of the successors of Sisebut to banish the whole nation from his dominions...But the tyrants were unwilling to dismiss the victims, whom they delighted to torture...'

Lord Acton told us in his essay 'Human Sacrifice':

'And yet, long after the last victim had fallen in honour of the sun-god of the Aztecs, the civilised nations of Christian Europe continued to wage wholesale destruction...Protestants and Catholics, clergy and laity, vied with each other for two hundred years to provide victims, and every refinement of legal ingenuity and torture was used in order to increase their number. In 1591, at Nördligen, a girl was tortured twenty-three times before she confessed...Three years later, in the same town, a woman suffered torture fifty-six times without confessing she was a witch."

Have a look at Acts 20. 29-31, 2 Thess 2, 1 Timothy 4. 1-4...

The denominations that give the bread and the wine to people who push...