Confusion is arising, perhaps deliberately, because of the different meanings of these words in scientific and colloquial use.

In scientific terms, an explanation which has not been tested by evidence is a hypothesis. Once it has been repeatedly proved by evidence and becomes generally accepted by the scientific community, it becomes a theory. To be scientific, a theory must always be subject to revision in the light of further evidence; it cannot claim to be the absolute truth, and no scientist would make such a claim, but it represents our current best understanding of the truth - which in colloquial terms is all we can ever mean by "true".

In these terms, evolution is a scientific theory which has been repeatedly tested by observation and experiment. Religious ideas about creation are hypotheses - explanations which are not proved, or even provable, by evidence. Despite this, their adherents often claim them to be the absolute truth.

I will not comment on which of these approaches is the more intellectually rigorous.