As Catholics, we believe that God knows the past, present, and future. But how exactly does He know all of this? We could give an easy answer by saying, “He’s God.”
While that’s true, we can actually say a lot more. Let’s dig deeper by examining the nature of time — something many of us get wrong.
Only by understanding time can we perceive how God knows the future.
1. What is time?
St. Thomas Aquinas had a strong view on the nature of time, which he mostly got from Aristotle. Aristotle believed time is just a measure of change.
When God created, He made things that are finite and subject to change. A human baby changes into a child and then an adult. Snow that falls on a winter day eventually transforms back to water as the temperature rises.
Time is simply how we measure these changes. The reason this is important is that we often think of time as something that exists on its own — something extra that is added into the mix. But this is not how St. Thomas and Aristotle saw time. For them, if there were no changing beings, there would be no time.
2. What is eternity?
Our view of eternity influences how we view God’s eternity. Many of us think of eternity as time on steroids — time that keeps going on and on in both directions. While this is one kind of eternity, it’s not the eternity we mean when we speak of God being eternal.
Remember that for St. Thomas, time is the measurement of change. But God is changeless. There is no transformation in Him to measure. He simply is.
For God, eternity is not time continually progressing forever. It is something many theologians speak of as an “eternal now.” This isn’t a perfect expression, since “now” is still connected to time. But it’s the closest we can get.