Presented for your edification.
The universe appears to be designed, this is a rationale derived from observation. There is the fine tuning of the universe, the inception of semantic information from which life further instantiates, the manifestation of a universal moral law that does not coincide with the natural world, and there are many other forms of sound observations. If the universe appears to be designed, then it is reasonable to conclude there is a designer, and that the designer is God. This is not a God of the gaps, but a God from first cause reasoning.
Theism is more rational than atheism, because atheism either cannot deal with first causes or it refuses to do so. Evolution, as an example, is a propositional systematic that proposes the emergence of new body plans from environmental pressure. And yet the advocates of this systematic have never adequately proposed how the evolutionary process can begin in the first place: any causal process must have a beginning. In order to prove an evolutionary beginning you would have to propose how life can emerge from environmental processes, and such proof cannot be obtained through lab experiments. Any lab experiment that requires a controlled environment and intelligent input cannot be used to prove environmental evolution.
Theists can provide logical evidences for the existence of God, but atheists can only provide mundane counters to those evidences: such as divine hiddenness, as if creation is hidden in some way. The reason that theists can present evidence is because theism is grounded in primary principles and first causes, whereas atheism has no interest in them. Primary principles being the most fundamental and irreducible propositions from which everything else is understood. Instead of reasoning from primary principles, atheists begin their rationale in the middle or toward the end of causal sequences. So atheism is a propositional systematic without any primary principles, and any systematic without primary principles is one that is not worth any consideration. Theism is the only systematic that is adequately reasoned in order to address first causes, and is therefore currently the only rational explanation for our existence.