They claim that the Bible has been corrupted by Jews and Christians. This has been their fall back technique since the very beginning. When Muhammad recognized that the locutions which he received from a spirit being did not jive with the Scripture, he simply claimed that the Scriptures had been corrupted. Today's apologists mirror the tactic of their prophet. Therefore, from the Muslim point of view, it follows of necessity that these Scriptures must have been corrupted.
Historical evidence makes no impression on the crushing force of the syllogism.
So it is, and it can be no other way. The Muslim controversialist feels no need to study evidence in detail. The Qur'an directs them to search the Old and New Testaments for the truth. Yet, when this truth disproves Islam, the same Qur'an condemns the Bible. The Muslim Secret Weapon Muslim apologists claim to have a secret weapon which proves that the Christian Scriptures have been corrupted.