Is the universe eternal?

Well recently I made a post about logically proving God exists and I included something about the universe beginning to exist and thus needing a cause, which is quite the first line of the Kalam cosmological argument.

I received many rebuttals but the rebuttal that made sense to me was guys saying the universe is eternal or has no beginning.

Here I will tell why the universe had a beginning and is not eternal. This is part of enforcing my previous post about logically proving God.

The universe is defined as all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy.

If the universe is all of space and time, then the universe has a beginning because time itself has a beginning, likewise space.

Time and space are both caused by matter. Merely looking at the definition of the universe, it is obvious that it is caused as far as science is involved. The universe actually began to exist and was caused.

If you all agree with this, then apply my former post and see why God is the cause of the universe.

(c) Eterigho Oghenekome Humphrey.