Verified answer

This question is being asked multiple times in minutely varying forms on YA! by various users and I have yet to see an answer that is both correct and particularly helpful (though there was one especially terse answer that came close). I'm answering it in hopes of putting a stop to the spamming of this question.

Due to the appearance of "necessarily", this argument can't be adequately translated into standard predicate logic. You have to use modal predicate logic. In addition you might want to use a tensed logic to capture more of the grammatical structure but nothing critical pertaining either to philosophical motivation or logical validity hinges on using tense logic, and doing so is rather ugly, so I'm not going to do so in what follows.

L will be the necessity operator. V will be universal quantification. E will be existential quantification. K will be "foreknows". g will be the proper name of god. P will be "comes to pass". You can figure the rest out.

Premise 1 would be something like L Vx(Kgx -> Px)

Premise 2 would be something like Kga

Notice that you don't actually need the "would come to pass" in "God foreknew that x would come to pass." in premise 2 ... it's redundant at best or, worse, changes the arity of K thus messing up the whole argument. All you need is "God foreknew that x.". Also notice that the variable "x" actually needs to be replaced by a specific name or event in premise 2. Otherwise the argument won't work at all and premise 2 won't even be a sentence (unless maybe you're dealing with second-order logic which unnecessarily complicates the translation).

The conclusion then is L (Pa) ... a comes to pass in all worlds.

This conclusion does NOT follow from the premises on at least most MPL systems. Pa follows but not L (Pa). However L (Pa) does follow if L (Kga) is true.

To show that L (Pa) doesn't follow from the given premises alone we can point out that premise 1 basically asks us to go to each world and perform a check: see if all the x which are Kg'd are P. Premise 1 is true just in case the check is passed at every world. However this leaves open the possibility that there's a world where no x are Kg'd (god knows nothing at that world), and so, even though the check gets passed (vacuously), that could be a world in which no x is P (nothing comes to pass!). Or, simpler, you could have god knowing all sorts of things but a just not exist at the world in question. In either case, "L (Pa)" would be false. Again though, L (Pa) would be true if we could guarantee that at every world Kga.

The natural (and tenseless) way of interpreting "comes to pass", "P", is to interpret it as an existence predicate such as Ex(x=y).

Another version of the question appearing elsewhere on YA! asks for a translation of the argument into a syllogistic form. All you have to do for that is to make the aforementioned change to premise 2 and also remove "necessarily" from premise 1 and the conclusion. If you do that then the argument is valid and the conclusion does follow from the premises.

A more detailed answer could be given, delving into logical questions of which modal system to best formulate the argument in, or into philosophical questions such as what can be known of other worlds, or questions of domain variability, quantifier scope, etc., but I see no reason to do that.

It's my experience that people who talk about things like necessity, god, and foreknowledge all in one or a few sentences think that they're talking about something profound. It's also my experience that those who can't clearly formulate what they're saying are very often actually thinking of something quite a bit simpler such as the facticity of knowledge (ie. knowledge isn't knowledge unless it's of something true). In a nutshell that appears to be what this whole thing is about ... whatever god (or for that matter anyone at all) knows will be true will be true. Why? For the simple reason that knowledge can't take false objects and still be knowledge. One might ask then whether the thing is really known at all, by god or anyone (ie. whether premise 2 is correct).

Very painful when kidney stone passes. Therefore, seek Extracorporeal Shock Wave Lithotripsy.

*JP is spammsering it in hopes of putting a stop to the spamming! Well done JP. Best spammser.

If God foreknew that x could come to move and something God foreknows involves move, then x will come to move. btw i do not like the ones useless phrases you employ. quit it jerk!