Aquinas said "If it were left solely to reason to seek the truth about God, few men would possess a knowledge of God." (Ch. 4, p. 4) Because true understanding of God can only be obtained with a level of knowledge un-possessed by the common man, the Church has been created to facilitate reason for man. This is done so that man can have faith in God. The achievement of faith requires one to have strong reason to possess such steadfast foundation in spite of the lofty ideas and ideals set forth by the Church which has supplied these as reason for Christians to use as an avenue for redemption and salvation for the past two thousand years, giving the common man a reason for faith in God.
"To know what reason can investigate concerning God requires that one already have a knowledge of many things, since almost all of philosophy is directed towards the knowledge of God."
(Ch. 4, p. 4) St. Thomas has demonstrated ways by which intellect grasps truth. And that God has played a role in every avenue that leads to truth. With that, God is the father, son and the Holy Spirit, and that he exists.
On whether the existence of God is self-evident; the objection states "if there is anything true, there must be truth. But God is truth itself. Therefore "God exists is self-evident."(newadvent.org) In reply to that objection; truth is the mind corresponding with reality. Intellect is having the truth and knowing that you have it and understanding why it is true. So we see truth is connected to knowledge and it works in way of our thinking. Truth distinguishes between individuals through their difference of opinions; however, it is something that everyone believes to be correct. Therefore, it depends on...