What is meant by existing in time is that one is constrained by time. You cannot go back in time and you cannot go forward in time. If someone can do either of those things he is not in time but instead lives in a state of timelessness.
I can do one of those things! I can go forward in time. I do it every second of every day. Does that make me timeless? I'd venture to say it does not. I can't go backward in time, at least as far as I know. I don't know if God can go backward in time, and I don't think you know that either. Maybe you can prove me wrong here. If we don't know from either any direct experience or biblical reference that God can actually move forward (greater than the rate we currently experience) or backward (at all) in time, then it's all pretty speculative, isn't it. The one verse you used before, "with the Lord, a day is as a thousand years, and a thousand years a day" only deals with forward motion of time, and as I explained, can easily be understood in regular terms and time passages that we can wrap our minds around.
I can also go forward in time with respect to other people and their time. It's a little hard to do, but Einstein laid out how to do it--either have greater gravity or travel at a faster speed than others, and you go forward in time, relatively. In other words, you stay younger than everybody else, so that when they are, say 10 days older, you might only be 9 days older, thus you jumped into the future by one day. Nobody knows how to go back unfortunately.
Can I offer you another way God might can be unconstrained by time? He outlasts it! In other words, when we wither like grass, God will still be going strong. When our great, great, great, grandchildren wither like grass, God will still be going strong. When our 20th generation grandchildren, assuming we are blessed in such a way, wither like grass, God will still be going strong. It seems like nothing can cause God to fade or grow weak or die. To me, that means He is unconstrained by time. And it seems like that is what the bible speaks of, too. That doesn't mean there aren't other things going on, but to select one of those other, more fanciful things, that doesn't have any clear description in the bible, when what I've presented does, seems like an appeal to something unknown and unexperienced and unreferenced in the Word. And maybe, just maybe, such an appeal is unnecessary. That's the beauty of Open Theism, imo.
I don't know how to explain the part where He has existed from eternity past. It's a mystery to me. Maybe someday I'll figure it out, or He'll tell me how it works.
The same can be said for the idea that the LORD can look into the future. If that is true then it is obvious that He is not constrained by time and therefore He exists in a state of timelessness.
What is not logical is to argue that the LORD lives in time but somehow He is able to get outside of time and look into the future.
You've now introduced another term "lives in time", that is just as hard to define as "outside of time".
But for the record, I have not ever said that the Lord can look into the future. I don't believe He can, because there isn't a thing called "future" just sitting out there waiting to be looked into, although Einstein and Boettner might disagree. I don't believe He needs to look into it. I think Arminians (see working definitions earlier in thread) use such language. I don't know of any scripture that supports or needs the idea, and I can think of at least one reason it doesn't make sense, which I expressed earlier. That is, if the Lord can look into the future, then the future exists as a finished product, but if it's a finished product, then God can't change the future--he's bound by it, and He has to let it complete. If He can change the future, then it isn't a finished product. Therefore it refutes itself. The Calvinist idea that God creates the future (and did so for every moment in time) is much more satisfactory, in that God maintains control over all events that way. The problem there is that God must then be responsible for every action, because He caused it to happen, and to maintain control, He must do everything and be the author of sin.
I think God put it on the line when He created us in His image--that we have the power to do something contrary to what He wants us to do. And I think God will punish those that deserve to be punished for not doing His will, and grant life to those that are willing to do His will, but not capable by themselves--thus needing Jesus Christ.
OK, give me your interpretation of the meaning of Acts 13:48.
Thanks!
Remember the story of the Good Samaritan? Remember how it came up? Jesus was asked, "Who is my neighbor?" because the expert in the law wanted to justify himself (Luke 10:29). The upshot was that the Samaritan's neighbor was the guy who helped. But the funny thing was that the wording always seemed a little weird. It's like the "neighbor" concept was a two-way street. TO have a neighbor, you had to be a neighbor. The wording just didn't quite fit the question Jesus was asked.
I don't really know for sure if I'm thinking the right way about Acts 13:48, but if God decided to save mankind, as long as the wanted to be saved; and if He decided it before the beginning of the world, but He isn't responsible for sin; then He probably set up this whole scheme of Jesus dying, with the possibility that nobody would believe and nobody would be saved, but if anybody did--if anybody decided to put their trust in Christ and His sacrifice--then those were the ones He set this all up for. Those are the ones that He chose before the foundation of the world--in Christ. And so, for those that believe, they were all taken care of from the beginning of the world, as many as believed. And they had been appointed to life long ages ago.
The wording is a little awkward. I won't do you the disservice of trying to interpret the Greek--more intelligent people than myself have done that. But I think it's just a little funny that the awkward wording in the story of the Good Samaritan and the awkward wording in the Acts 13:48 passage...were written by the same guy. Maybe there's nothing to that, or maybe there is something.
Thanks for putting up with me through all this. I hope I'm being clear in my writing, and that I'm not being disrespectful in my responses, even though I don't agree with you in some things. These discussions are valuable, I think.