Relatively Theory basically stipulates that whether an event is viewed as being in the past, present or future depends on where one is in relation to the event in question as well as how fast one is moving. Some people conclude from this that Relativity Theory lends support to the classical view of God in which God views all events of history as “an eternal now.” Since the open view of the future says that God faces a future partly comprised of possibilities, these people think Relativity Theory refutes the open view.
While this argument is commonly recited in books critical of the open view, it actually is based on a misunderstanding of Relativity Theory. Relativity Theory (both special and general relativity) apply only to finite points of reference within the space-time universe. An event “x” is past to one person, for example, present to another, and future to a third only because each of these people is a finite point of reference who is separated from the other two and who is (perhaps) traveling at a different velocity than the other two. Moreover, being separated from each other and the event in question, each must rely on light, traveling at a finite speed (186,000 miles per second) to convey information about the event. It is because of these conditions — and only because of these conditions — that each person experiences the time of the event in question differently.
But God, obviously, is not limited to any of these conditions. God is not finite, situated in one location over and against other locations or moving at a particular velocity. God is omnipresent—which means there is no distance between him and anything or any event in the universe. God is thus contemporary with every event. And so the timing of an event is not relative to God.
In other words, God knows when “now” is — in contrast to the past and future. God’s omnipresent “now” encompasses all the “nows” of every event and every point of reference. There is, therefore, a real past, a real future, and a real “now” for God. No finite point of reference — like a human being, for example — can have access to this “now.” For us, “when” an event happens is relative. But it is not for God.
An important aspect of the common misunderstanding of Relativity Theory is the mistaken idea that Relativity Theory applies to the future as well as to the present and past. It’s true that an event may lie in my future that is already present or past from other perspectives. Indeed, all events that a person experiences, other than those they themselves originate, are already past by the time they experience them, for it took light, traveling at a finite speed, to convey information about the event to them. But there is no perspective in which the events a person originates lie in the future for that person. Relativity theory actually rules out this possibility. In this sense Relativity Theory actually presupposes, rather than undermines, the reality of time.
So, there is nothing in Relativity Theory that argues against the Open View’s understanding that God faces a real future that is partly comprised of possibilities.
Perhaps the best book I’ve read that proves that Relativity Theory doesn’t undermine the reality of time is William Craig’s Time and Eternity. There’s also an excellent (but rather technical) discussion of Relativity Theory, arguing that it actually presupposes the reality of time rather than arguing against it, in Milic Capek’s, The Philosophical Impact of Contemporary Physics.