d.choe, your Aquinas’ First Cause Argument has made some large assumptions to bridge the gaps in the logic. Assumptions that can never be proven. And of course its going to have that conclusion since he was a medieval priest!
it assumes that there was no cause to the 'First cause'... hence a god. but fails to see that its possible for their to be no first cause, simple an infinite series of causes. in his argument he mentions this but simply says "not possible".