Did God Know the Future of Fighting?

Before I address your question, I will like to say that generally the decision of accepting or leaving Islam should not be taken because of such a narrow issue. I call it narrow because it is also possible that you are unable to understand one verse or an issue that is brought up in Quran. Instead, when we accept a religion, we should base our decision on the content of the entire religion and all its scriptures as opposed to a few verses or issues.

In this particular case, I can see that this issue is being linked directly with some of God's attributes, specifically His omniscience. We must still consider the rest of the content of Quran to see where and how His these attributes are justified, or better yet, proven. One example is that God informed the opponents of Muhammad (pbuh) that all the nations that opposed a messenger of God were actually dealt by the Almighty by having punished them in this world (Quran 10:47). Opponents of prophet Muhammad (pbuh) were initially informed that after having been convinced of the truth, if they did not accept Muhammad (pbuh) as a messenger of God, they shall be dealt with in this world too (Quran 10:48-49). Even after that when his opponents did not accept his message, God did help Muslims annhilate idolaters from the Arabian peninsula and guided them so that they became politically dominant in the region and people of the book politically subservient to them. Indeed, it is this and many other similar facts that have been put forth by Quran as proof of Muhammad (pbuh) being a messenger of God that we should keep in mind too. If a verse such as the one you have quoted is not clear, then that thing shall be judged in light of the rest of the teachings.

Having said that, let me translate the verses that you have mentioned and then discuss the issues brought up:

Now the phrases that have caused the confusion are "if they fight you" and "if they cease". There are multiple issues for why these phrases are used this way:

Firstly this construction is used not because God does or does not know what is going to happen, but because it is a directive for Muslims and Muslims are being given guidelines on when they should attack and when they should not. So, they are being told that when they are attacked, then they should fight back, but when the adversary ceases, then they must do the same too. In other words, Muslims do not know when can they be attacked, so the guideline is such that whenever they are attacked, it can be used. Of course, being Omniscient, God could have listed all the incidents where enemy could have attacked and how Muslims should behave, but that would not have been as useful because in this way, a general principle is laid down that can be used whenever possible. This confusion can also be alleviated if we replace the phrases "if they fight" and "if they cease" with "when they fight" and "when they cease". The Arabic phrase used allows this translation. In such a case, one of the verses would then read as:

Given this understanding, it shall also address the second part of the question, this phrase "and if they cease" clearly implies to fighting that is being discussed in the preceding verses. In other words, whenever the adversary of Muslims at that time ceased fighting, then Muslims should cease too, and then they will be judged by God on their behavior. I do not think these verses are directly related to whether the adversay was from among the people of the book or from among the idolaters.

Secondly, it is a known fact that man is in trial in this world. As a result, man does not know the future, has to make decisions and control his actions, without having perfect knowledge. If we carefully analyze the verses above, we see that God, in all His Wisdom, has given the choices as per his law to both the non-Muslims and Muslims in the above verses. In other words, while He knows what is going to happen in the future, He has let non-Muslims make the choice of when to fight and when not to and also laid down the consequences of their action. Similarly, He has also given a choice to Muslims on when to fight back and when not to. This is consistent with anything else that God has ordained in this world. For instance, we do not know about the future even though God does, but He chooses not to inform us of the future and what choices we should make. We just have the guidelines on how to succeed in this world and whenever a situation arises, we make the judgment and behave accordingly. Indeed, this is the trial of this world.

Finally, the entire Quran is not meant only for the time of Muhammad (pbuh). Most of these directives are laid down as general principles. Whenever a situation arrived in prophet's (pbuh) time, the directives were given in a way that allowed Muslims to derive guidance from them in later times as well. The verses under discussion also exhibit this property, they present a general principle so that even when the doors for revelation were closed after prophet Muhammad (pbuh)'s demise, we could still judge our everyday problems against Quran and pick an appropriate course of action.

In summary, I will say that the style chosen by Quran is the best one, the one that challenged the Arabs of that time. These verses were not meant to address the issue that has been raised by you. For that particular issue, there are other verses that discuss it. These verses were meant to lay down a general principle regarding engagement with adversary under different conditions in the best possible manner.