Prophecy is the primary proof that any Scripture is sent from God. It's a miracle that can be witnessed by anyone, even thousands of years after it is written.
This article will look at a single passage that is most often claimed by Muslims to be a fulfilled future prophecy in the Quran, and examine whether it meets that criteria.
In Surah 30, we read:
Surah 30:2-5
2 The Romans have been defeated
3 in a nearby land. Yet following their defeat, they will triumph
4 within three to nine years. The ˹whole˺ matter rests with Allah before and after ˹victory˺. And on that day the believers will rejoice
5 at the victory willed by Allah. He gives victory to whoever He wills. For He is the Almighty, Most Merciful.
From the above, we see that this is clearly portrayed as a prophecy about a Roman victory. However, immediately we can recognize the vagueness of the prophecy, in the following ways:
This prophecy is also about an event which has a binary outcome - like a coin-flip. The outcome of a battle can be primarily described as victory, or defeat, depending on whether the attacking side accomplished its objective, yet even then, either side can still claim that they won. Picking one of two possible outcomes, especially in vague circumstances like these, is not impressive. It's been done by tens of thousands of military practitioners, over the course of thousands of years.
Also, we can recognize that even if the Romans lost 100 battles after this one, it would only take a single victory, no matter how small, for Muhammad to claim that the prophecy had been fulfilled. Therefore, not only is it a coin-flip, but you get the flip the coin over and over again, because we are just looking for a "victory".
Furthermore, notice that the prophecy doesn't have any theological significance at all, and actually contravenes a theme of Islam, which is that Allah doesn't guide or love the disbelievers (Surah 3:32, 8:55, 9:37, etc.). I thought the Romans were the Kuffar? Why would Muslims rejoice when they win in battle?
However, even discounting all of the above, according to Islam's own sources, this was a retroactive prophecy:
Jami at-Tirmidhi 3192
Narrated Atiyyah:
Abu Sa'eed narrated: "On the Day of Badr, the Romans had a victory over the Persians. So the believers were pleased with that, then the following was revealed: 'Alif Lam Mim. The Romans have been defeated, up to His saying: 'the believers will rejoice - with the help of Allah... (30:1-5)'" He said: "So the believers were happy with the victory of the Romans over the Persians."
Above, a companion of Muhammad testifies that Muhammad gave the "prophecy" on the day that the Romans defeated the Persians. That's not how prophecy works. Calling this a "prophecy", and even presenting it in the way that it's presented in the Quran, is absolutely deceptive.
Therefore, not only is the prophecy too vague to be impressive, and not only is it a coin-flip with lots of allowance for failure built in, but it was also a fake prophecy, given after the event took place.
The Quran is bereft of any fulfilled future prophecy. Instead, it's a scatterbrained text which consists of endlessly repetitive rules, vague exaltations of God, poorly-retold Bible stories and local legends, and judgments on earthly affairs, which in the final estimation, anyone could have written. The only things that could be called "prophecy" pertain to the afterlife, which no one can verify.
Muhammad had to write a book like this, because he was a false prophet, who did not have divine revelation.