Through reason alone, as demonstrated by Peter Kreeft in his Extremely Brief Summary of 24 Arguments, one can arrive at the following ways of considering God:
• Most perfect conceivable Being
• First Mover
• Uncaused Cause
• Intelligent Designer
• Highest degree of perfection
• Necessary basis of contingent beings
• Big Banger: Cause of beginning of time
• Cause of the idea of perfect being
• Authoritative Voice of conscience
• Eternal, objective and absolute Truth
• Meaning of life
• Beauty revealed by beauty
• Cause of mystical experience
• Perfect moral Ideal
• Object of innate desire
• Provident Guide
• Dialogue Partner in prayer
• Object of belief of wise people
• Joy and power of saints
• Only chance of winning eternal happiness
It's good to review Kreeft's Extremely Brief Summary of 24 Arguments of God's Existence, because they offer us a deeper glimpse of the object of our love. And as we know from our Catechism: "Faith seeks understanding": it is intrinsic to faith that a believer desires to know better the One in whom he has put his faith, and to understand better what He has revealed; a more penetrating knowledge will in turn call forth a greater faith, increasingly set afire by love.
For me, it is quite moving to be able to name God in all these ways, given Kreeft's attempt at comprehensiveness and at a cumulative probative effect. Of course, nothing beats deeper knowledge based on the data of Revelation through the perfect Communication of God himself, Jesus Christ.
But for those who love God, any additional information about him, even at the level of reason alone -- and in this case one of the most comprehensive attempts to summarize what we can know of God through sheer human intelligence -- can help us fall in love with him with more passion.
And for those who don't, these can help convince them to start on the road of loving him until they reach the goal of loving him as he asked us to: with all your heart, all your soul, all your mind and all your strength.
God is the Logos. Our efforts to use the spark of reason within us to reach Him who is Reason Himself will surely please Him.