Evidence for the existence of God is found in what He’s done, things no one else could possibly do. (Ps 109:27) It’s based on the Law of Cause and Effect; that every effect, everything that comes into being or begins to exist, has a distinct cause. The cause is distinct from the effect; the cause is not the same as the effect; the cause is something other than or different from the effect. If the cause can’t be natural, then it must be supernatural: God must be the Cause.
The Kalam Cosmological Argument, the primary way of establishing the existence of God (Ro 1:20-21), is based on this law:
- Everything that comes into being has a cause.
- The universe came into being.
- Therefore the universe has a cause.
Premise 1 is merely a restatement of the Law of Cause and Effect, which forms the basis of all scientific inquiry. We presuppose it whenever we’re trying to understand an occurrence or event. When we’re being honest, we never suppose something (an effect) just is, that it’s causeless. We instinctively ask How? looking for the cause. People only deny this law when they’re biased, averse to the implications – and there’s just one scenario like this: when the Cause is God. We find the idea absurd otherwise; it opposes science itself.
Premise 2 is true because if Nature (i.e. everything that is natural) is infinitely old then it would be at steady state with no usable energy (due to the 2nd Law of Thermodynamics), and it’s not. Since Nature is not infinitely old, it must have come into being.
So, the universe, or Nature, the entire space-time continuum, came into being; therefore it had a cause. Nature could not have caused itself since effects must be distinct from their causes; the cause of all of Nature must therefore be distinct from and separate from all of Nature. Thus, the cause of Nature cannot be natural; it must be non-physical, beyond space and time: spiritual, supernatural. We call this supernatural, spiritual Cause of Nature: God.
Here is a typical attempt to refute the Kalam Cosmological Argument (KCA).
He starts by asserting that KCA is trivial and uninteresting, since it provides no evidence of an un-caused cause, or of a supernatural cause. He thus admits to his inability to perceive KCA’s profound implications, that any cause of our universe must be unlike anything we call Nature, an agent outside space and time, immaterial, non-physical, of essentially infinite power. We have only one expression to capture such a thing: spiritual. Ascribing to such an agent sentience, intelligence, will and omnipotence is no stretch at all when we carefully consider the alternative.
A very good response to this refutation of KCA can be found here.
Here is a rebuttal to the most common (unscholarly) objections to KCA by Dr. William Lane Craig that is easily understood.
https://www.youtube.com/watch?v=gtfVds8Kn4s