Infinity

Today, I was mock debating myself on the origin of the universe, and I came upon the question "how can time not have a beginning?"

The main point of this argument was to show time cannot progress if there is no beginning, but then I thought about the closest infinite parallel, numbers. We can progress from 1 to 2 to 3 and so on, so why can't we progress in time?

At this time my brain began to smart.

Then my question changed to, in our reality do we have anything actually infinite? For the sake of the argument, we'll say no. We don't have an infinite number of atoms, we just have a very large number of atoms. So if numbers (of things) in our physical reality aren't infinite, than can time (which is part of our reality) be infinite? You may say "but numbers are infinite, you can keep counting forever!" And I say that it is all hypothetical. Numbers to infinity are a concept, not a reality, in the same way a straight line or a perfect circle are concepts. In our reality they don't actually exist. So, in physical time-space reality, infinity doesn't exist, so there had to be a beginning, and then what started it all? Who was the first cause? At this time, we must look beyond this silly little argument and to religion...(hint: Christianity)