Forgive me for this, but my bit of knowledge on the issue originates from studying the Kalam Cosmological Argument (which I'm not trying to present here).
You might first ask, has time always existed or not?
If so, then starting from this point in time, time goes back an infinite amount. That is, as I understand it, problematic though. A thought experiment starring Aqua Man
Imagine one of those swimming competitions where the swimmers swim to the opposite wall and back. Let the opposite wall represent the infinite past and the starting wall the present moment.
Ready. Set. Go!
AquaMan jumps in and swims as fast as he can to the opposite wall and back (far out-swimming all his competitors by the way).
The question is how long does it take him to finish the race? How long does it take to arrive at the present moment? It seems that he wouldn't. In fact, he never even reaches the opposite wall despite his powers. This is because if the past stretches back to infinity, there is no wall. That's problematic, though if one holds that time has always existed (even if a multiverse if one want to go there) since we've clearly arrived at the present moment.
If time hasn't always existed, we're left with a timeless cause.
You might first ask, has time always existed or not?
If so, then starting from this point in time, time goes back an infinite amount. That is, as I understand it, problematic though. A thought experiment starring Aqua Man
Imagine one of those swimming competitions where the swimmers swim to the opposite wall and back. Let the opposite wall represent the infinite past and the starting wall the present moment.
Ready. Set. Go!
AquaMan jumps in and swims as fast as he can to the opposite wall and back (far out-swimming all his competitors by the way).
The question is how long does it take him to finish the race? How long does it take to arrive at the present moment? It seems that he wouldn't. In fact, he never even reaches the opposite wall despite his powers. This is because if the past stretches back to infinity, there is no wall. That's problematic, though if one holds that time has always existed (even if a multiverse if one want to go there) since we've clearly arrived at the present moment.
If time hasn't always existed, we're left with a timeless cause.