The dilemma depends on a premise Islam does not teach: that Allah promised to preserve every earlier scripture in its later transmitted form. The Quran affirms the divine origin of the Torah and Gospel, but gives a special promise of preservation to the Quran as the final revelation.
The objection stated fairly
The critic argues that Muslims cannot have it both ways. If Allah revealed the Torah and Gospel as guidance, why did He allow their texts to be altered? If He could not prevent corruption, that suggests weakness. If He allowed it while judging people by the result, that suggests injustice. The critic also points to an apparent double standard: Muslims appeal to academic textual criticism when discussing the Bible, but reject conclusions from similar scholarship when it concerns the Quran.
What the Quran actually claims
The Quran does not say that every copy or later edition of the earlier scriptures would remain perfectly preserved. It says that Allah revealed them and that they contained guidance:
Indeed, We sent down the Torah, in which was guidance and light.
Quran 5:44
And We sent, following in their footsteps, Jesus, son of Mary, confirming the Torah that came before him, and We gave him the Gospel in which was guidance and light.
Quran 5:46
At the same time, the Quran describes some People of the Book as concealing, forgetting, misreading, or altering parts of what they had received. Classical scholars discussed both interpretive distortion and textual alteration. They did not therefore conclude that every sentence in the present Bible is false. Rather, the original revelation is not identical to the entire later textual collection.
The promise of preservation is stated specifically about the Quran:
Indeed, We have sent down the Quran, and indeed, We will be its guardian.
Quran 15:9
This difference is not a weakness in the argument. A final, universal revelation requires a different mode of preservation from earlier revelations given to particular communities for particular periods. Allah can permit a text to pass through human custody while later sending a protected criterion to confirm what remains true and expose what has been changed.
Permission is not approval, and judgment is not arbitrary
Allowing human beings to alter or conceal revelation does not mean Allah approves of their wrongdoing. Human freedom and responsibility operate throughout the Quran. Nor does Islam teach that people are judged simply for possessing a corrupted document. The Quran criticizes people for knowingly hiding truth, rejecting God's messengers, and following false interpretations. Those who lived before the final message were accountable according to the revelation and evidence available to them.
Textual criticism can legitimately establish that biblical manuscripts contain variants. Muslims should accept evidence consistently. But accepting manuscript evidence does not require accepting every philosophical conclusion drawn from it. The Quran also has a distinct preservation history, including widespread memorization and continuous public recitation from the beginning, so the two cases cannot be treated as identical by assumption.
The argument therefore establishes a challenge about how revelation was transmitted, not a contradiction in Islam. It would succeed only if Allah had promised to preserve the earlier scriptures exactly as later communities transmitted them, and the Quran makes no such promise.