As previously posted, one of the strongest pieces of evidence for the existence of God is in the fact that a concept of God or higher intelligence has existed and exists within every culture that we can identify in the historical record of Earth. And for those who choose not to believe in God or a higher intelligence, there are few, if any, things on Earth that produce more passion and determination to deny that something exists.
Then we begin narrowing down concepts in such a way that such a brilliant mind as Einstein, who did not accept the concept of a personal God who is specifically mindful of him, came to the conclusion that the very order of the universe was such to belie any reasonable mathematical possibility of it all happening purely by chance. His conclusion is that there is an intelligence within the whole guiding the process.
Taking the cosmological (cause and effect) argument for an intelligent designer alone:
We can rationally conclude that the universe exists. And that allows for three possibilities:
(a) It created itself
(b) It always existed
(c) It was created by an eternal being
Argument (a) is irrational as if nothing created itself, it had to be something and nothing at the same time, which violates the scientific law of contradiction.
Argument (b) is a possibility; however, the science that we have strongly suggests that the universe had a beginning. If we conclude that there was no beginning, we are going to have to throw out a whole lot of science books.
That leave us with Argument (c) that the universe came about as a result of a self-existent being. In short, the universe is an effect, and a self-existent force, intelligence, or "God" is its cause. That is the most rational of the three arguments.