While it is true that the question of the existence of God is one of faith in the existence, with a a structured hypothesis one can go about ascertaining the probability that a God who is able to communicate and also willing to communicate with humans does exist in my view.
So the idea is to develop one’s own theology based on one's convictions and put it to the test; see if things can be proven and work out for the best for one in terms of the mission that one undertakes in life.
If the mission is noble, and there is a God who supports the quest of the mission He will ensure that the mission is accomplished as truth.
The only way to find out the Reality is to examine one's own mind for that Mind is the source of all knowledge which analyses the material world in conjunction with the spiritual realm of existence.
Going back to square one, we are all animals in the jungle of Nature so there are no reasons for the division of humanity between good, the bad and the ugly elements that we know to exist in Nature. It is not selection of the genes fittest to the environment or else the evil element will predominate societies and the good and routinal elements will be wiped out just like the dinosaurs who grew too vicious and large on the Planet Earth. The fact that as a global humanity the good, the bad and the ugly can still live together within societies and globally should be seen as evidence that there are other forces at play from the spiritual dimension.
The mind needs to be free from the shackles of restrictions imposed upon it from one's beliefs, missions, ambitions, plans, objectives, duties, responsibilities, schemes, tactics, ulterior motives, karma, dharma etc to be able to free flow in freethought and free-rationalism in order to know how one needs to determine the truth through a yoga of truth accommodation going forwards with a set of hypothesised criteria that one continually tests and reviews to turn one's faith into devotion (bhakti) if one is lucky enough get to this promised land of mukti/nirvana/moksha where there is sheer ‘ananda’ or happiness and one is stoical to the miseries that life throws at one because one has determined that pre-ordained and pre-orchestrated nature of the events in the universe and navigating myself thus nonchalantly, spontaneously and unpremeditatedly in whatever one does each moment of the day. This is being 'fatist' and not having a fatalist approach to living believeing in one's life having been pre-determined by the manner with which God has created the universe and the universe is moving along ahead.
Never say never again will I not be a theist for without faith there in knowledge to be had/gained. It is all within one's mind. The mind has to raise itself from the lower place to a higher plane by losing all one's attachments to operate at the interface between the mind and the Supermind (OM)/God, so that one is still in control of one’s material circumstances yet having access to the totality of awareness of one's circumstances and with a therefore sharpened intellect to deal with the evil elements of Nature with the required survival instinct needed.
That is how one is liberated from the samsara yet living fully immersed in Creation at the rajasic mode of travel and not the sattvic or tamasic modes which are destructive to Nature. If one perfects this raison d’etre, God has His way of Protecting and Saving the religious person practicing this way of living as the religion of Vaishnavism set according to the philosophical criteria of Vishista Advaita Vedanta.