Every Catholic knows (or should know) the Apostle’s Creed, the Ten Commandments, the seven Sacraments of our holy Faith.  The Apostle’s Creed summarizes what we are to believe as Catholics; the Ten Commandments outline what we are to do or not do as Catholics; and the seven Sacraments enable us to believe and to do (or not do) as we ought to fulfill our obligations to God Almighty and save our souls.

Today, we begin an exposition of the Apostolic Creed of the Church.

“I believe in God, the Father Almighty, Creator of heaven and earth” is the first article of the Apostle’s Creed.

When we say, “I believe” we assent to what we consider to be a fact (not an opinion), without the slightest doubt or suspicion that we might be wrong.  We say this concerning natural things based on the certitude of the senses as “ I believe myself to be in Texas” could equally be said, “I am in Texas”; but more, and in religious things, we believe this way because God has revealed it Who can neither deceive nor be deceived.  Indeed, what God has revealed is more reliable than our senses i.e., the Real Presence. 

“I believe in God” states our belief in a Divine Being.  “God” is the name which identifies that pre-existing, uncreated, infinite Being upon which all else depends.  God alone is He Who cannot not exist; God is the only necessary being.  Said another way, the essence of God, what He is in Himself, is to exist.

St. Thomas Aquinas tells us that the natural man can know that God exists in a general and confused way.  And although by divine revelation man can know much more about God with greater clarity, mankind can still know that God exists as the ultimate principle to whom obligations are due... which is the staring point of religion.  King David wrote, “the fool has said in his heart, ‘There is no God,’” (Ps 52:1) in reference to the natural man who has the ability to understand that God exists but does not use it to discover that God exists. 
    
In his Summa Theologica (I.Q.2,a.3), St. Thomas demonstrates five ways by which the natural man (without divine revelation) can know that God exists. His arguments concern motion, efficient causes, contingency, gradation, and governance.  We will summarize them.

 The first and more clear example is derived from the argument of motion.  Our senses perceive motion in the world.  Now whatever is in motion must have been put into motion by something else; something has to be given motion to have motion.  Nor, however, can a thing be moved and mover for this involves a contradiction.  For while water is actually hot when boiled and potentially cold at the same time (which will happen when the heat is removed), it is not actually hot and potentially hot at the same time; boiled water cannot be simultaneously actually hot and potentially hot in the same way, but only in different respects (more hot, less hot).  Just so, it is impossible that a thing should be both mover and moved i.e., that it should move itself.   So if  something has motion it necessitates a mover; but any arrangement which produces an infinity of movers only takes us back into infinity.  Therefore, there must needs be a first mover, put into motion by no other, who is God.

The second way involves the nature of efficient cause.  In this world there is an order of causes.  A thing does not cause itself but is caused by something else i.e., I came from parents, not myself.  Again, it is impossible that efficient causes go back into infinity for in all things we find an order of causes, a first, then intermediate(s), and finally, an ultimate cause.  If there is no first cause, there will be no intermediate cause, nor final cause of things which is plainly false.  Therefore, there must be a first efficient cause, preceding all other causes, who is God.

The third way involves possibility and necessity.  There is contingency in nature; things in nature do not have to be.  As things are generated, corrupted, and put out of existence so it is possible to be and not to be.  Nor have natural things always existed.  For if everything is possible not to be then, at one time, there must have been nothing at all; and if there was nothing at one time then there would be absolutely nothing in existence even now.  But things do exist.  Therefore, there must be some things which are necessary.  And of all these necessary things, there must be one to explain them all.  Therefore, there must be an absolutely necessary being which cannot not be, who is God.

The fourth way involves gradation of things.  Among beings there are some more or less good, true, noble, and such like.  When we say of something that it is good, better, or best... we speak relative to its perfection i.e., a thing is said to be hotter in reference to that which is hottest. In this way, therefore, there must be something which gives rise to the perfection of everything else, a thing perfectly good, perfectly true, having all perfections, who is God.

The fifth way involves governance in the world.  In this world, we see things which lack intelligence, such as natural bodies, acting for specific ends as if they had intelligence as evident by them always acting in the same way so as to obtain the best result, i.e. microbes, a tomato plant. Now something which lacks intelligence cannot act for an end, - a microbe cannot knowingly digest a hamburger or cause an illness; a plant does not knowingly grow, produce fruit, resist decay - unless it is directed to by someone with intelligence, i.e. as an arrow is shot to its mark by an archer.  Therefore, there must needs be some supreme intelligence who directs natural things to their ends, and this we call God.

In brief, these are the five ways St. Thomas uses to prove the existence of God.  They are subtle arguments.  Perhaps the argument of an old Spanish woman will be more accessible. 

During the communist revolution in Spain, a communist soldier accosted this pious woman saying, “We (the communists) will destroy your belief in God.  We will raze your churches, smash your altars and break your statues; we will burn your books and vestments; kill your priests; disband the religious...”
“Oh,” she answered, “if you want me to disbelieve in God, you will have to do more than that; you will have to rip the all the stars out of heaven; you will have to cause the sun not to shine.”