The idea of God always existing

[Undeceived]

3. A personal, eternal, causeless being created the universe. He/she did not "come into existence", but always was.

"Why not save a step and say the universe always was?"

Because our natural laws say that energy cannot always have been. No beginning = scientific contradiction. We need a causal agent that is by definition supernatural (meaning outside of the natural system) so that there is no contradiction with natural laws. God fits the bill. All natural things are caused, but a supernatural being or force would not have to be caused, because they are spiritual and do not require physical energy. The causal agent has to be eternal, and eternal means unchanging (again, all changes have causes and we can't logically have infinite causes). Our universe is always changing, and its entropy is increasing, meaning the energy is running down from one starting point. What caused that spike in energy, that it is able to run down over time?

Entropy: a measure inversely related to the energy available for work in a physical system. So imagine the line above running in a downwards slope from the beginning of time.

Or, if he "always was" would not an infinite amount of time have had to pass to reach this point?

God is changeless, so time does not exist for him. He is always in the present. He made time for our world so we could learn and make choices--so we could change.