Observable evidence is everywhere even in science and the logical design of even the simplest of organisms through the diversity of life... It's amazing so many are so blind to it.
I have thought about this many times over the years, and it is probably the single most important concept that leads me to reject the idea of a Creator. The size, diversity, natural beauty, natural horror of the universe is so vast, so awesome, so beautiful, yet so careless, so unforgiving, that it could only be created naturally.
Also the fact that the slice of time in which life can subsist in this universe is infinitesimally small compared to the projected time the universe will exist. It makes no sense to consciously create such a universe, considering it is only life observing the universe that makes it worthwhile. Unless the Creator gets his kicks watching a lifeless universe slowly die over an incomprehensible length of time.