The Fourth Way we can know that God exists.
Updated: Aug 5, 2021
The Fourth Way we can know that God is real!
© 2021 Patrick C. Marks, All rights reserved
The following is a preview from the FAQ section of my new book…
The Bible teaches that what can be known about what God is like can be understood from what has been made. Romans 1:19 teaches that everything existing today makes it clear God must be real and what has been created also tell us about who God is. In the Middle Ages, a monk named Thomas Aquinas showed five logical ways everyone can see what Romans 1:19 is teaching.
Aquinas’s Fourth Way explains why there must be a best or a coldest or a maximum of any kind of thing. He noticed that in the world all around us, everything anyone runs into is never totally perfect or completely the maximum in every way. People seem to know this without thinking about it very much. If you see a flower, it is easy to see what is imperfect about the flower – maybe it is not exactly evenly colored, or some petals are larger than others and so on. But if you notice the imperfections, it is only because you must have some idea of what is perfect.
Aquinas also pointed out - in his first, second and third ways - that there are only two kinds of beings in the universe: those things which began to exist and that which must be eternal and has always existed. But what does it mean if only these two kinds of beings exist, but we know intuitively that there must be something that is truest or best or the maximum? Since everything we observe in the universe is somehow less than the maximum or is imperfect in comparison to something, Aquinas realized that the concept of “the maximum” demonstrates something about the Creator Being who has always existed. Since the eternal Being is the source of everything that is less than the maximum, it follows that the eternal Creator must Himself be the maximum or the perfection of everything. This is so because an effect can only have what it gets from the cause. So, if everything that begins to exist is less than perfect, then the eternal source must be what is perfect. Since everything that begins to exist lacks perfection, but every effect needs an ultimate, uncaused efficient cause, it follows that God must have within Himself all the perfections that every other thing lacks.
But if we know intuitively that the ultimate perfect Being must exist because there are imperfect things that began to exist all around us, then it makes sense from created things that the perfect, eternal, Creator God must exist.
The Fourth Way implies that God’s being (His existence), His power and His perfection must exceed the being (existence) or power or perfection of everything else. No star, no supernova, not all the combined energy of the entire universe can exceed His power because He is the Cause.
“The Fourth Way explains maximum standards can show, that God is the Cause, He’s the max we can know.”
There must be a best or a maximum of any kind of thing but in the universe, what we see is never totally perfect or completely the maximum. This means there must be a maximal cause of everything because all contingent beings (beings that begin to exist) are less than perfect. Since every effect needs an ultimate cause, it follows that God must have within Himself all the perfections that every other thing lacks.
More or less are predicated of different things, according as they resemble in their different ways something which is the maximum…so that there is something which is truest, something best, something noblest, and consequently, something which is uttermost being…there must also be something which is to all beings the cause of their being, goodness, and every other perfection; and this we call God. 
 Aquinas, Summa Theologica, 14.