A Muslim may say:
Christians believe in a corrupted scripture. The Quran is the only preserved scripture and the Bible is corrupted.
If so, it is a confusing statement to say that God’s previous words (the Bible) were corrupted, while God’s last word (the Quran)-according to Islamic beliefs-were preserved.
In a way, you are saying that some of God’s words could be preserved, while others could be corrupted? (read my article “Is the Quran Preserved?“)
In other words we accuse God of being powerless (unable to protect His previous words) and/or unfair (for not caring to preserve His previous words and letting people be misled while preserving the last word He sent).
We need to choose, is God mighty and just or is He powerless and unfair?
We believe God is mighty and just, and whatever message He sends He is able to protect and preserve. Any tampering with this message is an insult to Him.
We also have to ask ourselves. When did this alleged corruption happen?
Was it before the time of Muhammad?
Well, that is impossible since the Quran refers to Bible as a true scripture in a lot of verses. For example, God says to Muhammad in the Quran regarding the Jews:
But how do they come to you for decision while they have the Torah, in which is the Decision of God? (Quran 5:43)
If the Torah (the first five books of the Bible) were corrupted, then why does the Quran refers to it as an authentic carrier of God’s decision?!
Therefore, we cannot say the Bible was corrupted before the time of Muhammad.
Was it corrupted after Muhammad claimed to be a prophet?
If the Quran accused the people of the book of corrupting their scripture (e.g. Quran 4:46; 5:13; 5:41), it might have been an accusation to a local group but not to the entire Jewish and Christian world. The Jewish and Christian world was thousands of times bigger than the village of Medina in the desert of Arabia where this accusation occurred.
In order for the Jews and the Christians to corrupt their scripture, they would have had to call a universal conference (bring all the leaders of their religion from all the known world at that time, Asia, Europe, and Africa) to meet in one place and decide what to remove. Then they would have had to burn thousands or even hundreds of thousands of books of scripture from all around the world; and then produce thousands of modified books of scripture to be re-distributed back to the entire known world.
This is logistically impossible, even in our current time. It is also morally difficult, because thousands of religious leaders would have had to choose to tamper with their God’s word knowingly. Is it not conceivable that at least a few of the leaders would have rejected such tampering? Furthermore, would not some of these scriptures have escaped these modifications and we would have found them by now?
We are also talking about two adversaries, Jews and Christians. They were not good friends of each other at the time.
If the Jews corrupted the Jewish scripture, then the Christians who believed in it would not be silent. On the other hand, the Jews would not keep quiet if the Christians tampered with the Jewish scripture, as it is their scripture; and they (the Jews) would defiantly find something against the Christians if they (Christians) tampered with the Christian scripture.
Again you would have to get these two adversarial groups together and then get them to agree on changing their own scripture. Do you think there were no believers who considered God’s command?
You shall not add to the word that I command you, nor take from it, that you may keep the commandments of the Lord your God that I command you. (Deuteronomy 4:2)
God is good, honest, mighty and just. He would not let His word be tampered with and allow people to be led astray, while He did nothing for 600 years until He sent a new prophet with a new scripture.
I warn everyone who hears the words of the prophecy of this book: if anyone adds to them, God will add to him the plagues described in this book, and if anyone takes away from the words of the book of this prophecy, God will take away his share in the tree of life and in the holy city, which are described in this book. (Revelation 22:18-19)
Nobody can tamper with God’s word without experiencing God’s wrath.
I invite you to read the word of God (the Bible) for yourself.