God's Trinitarian Nature
Clearly Shown to Us in the Testimony of Creation
"For the invisible things of him from the creation of the world are clearly seen, being understood by the things which are made, even his eternal power and Godhead; so that they are without excuse." (Romans 1:20)
This verse of the Bible tells us that the very nature of God, His power and His Godhead (a term referring to the nature of His divinity) are clearly seen by looking at the way creation is set up. God has given a testimony of Himself to us through nature, if we will only open our minds and hearts to look and understand.
The very fundamental existence of our universe testifies to the trinitarian Godhead.
The Fundamentals of the Universe
Our universe (by which I mean, broadly, all that exists that has been created) has three intricately woven parts: Space, time, and matter/energy. For the universe to exist as we know it, all three are required, we simply cannot imagine an existence without any one of these three components. The three are intricately connected, and we can rightly say that without any one of the three, the universe would not exist.
SPACE - Imagine, if you will, a universe which has time and matter/energy, but no space. By space is meant EXTENSION in the various directions, not the place where Mars and Jupiter and the stars are. Imagine a universe that did not have any extension in any direction whatsoever. You can't. It exceeds the ability and capacity of the human mind. You can say that all of the matter/energy, and its time frame relation, would be compressed to a point, but even then, that isn't TRULY a right understanding of this scenario since even a point has extension in at least one dimension. Such a universe simply could not be conceived of by us. For us to be able to even perceive the universe we live in, our minds need for there to be space, extension.
TIME - Imagine a universe with space and matter/energy, but no time. Again, you can't. We can't even say that "everything would happen at once" or "everything would be frozen in time", because those understandings still preclude the sequential progression of events which we call "time", just jumbled together or halted at some point. Time is absolutely essential for us to understand and perceive the universe we live in, and it couldn't exist for us in any meaningful way without time.
MATTER/ENERGY - The matter/energy complex (which these are really the same thing, as E=mc^2 tells us, since they can be interconverted back and forth, at least theoretically), if missing from the universe, would again render the universe meaningless. With space and time, but no matter/energy, the universe would be an absolute void and would be completely unapproachable in understanding. We cannot even really comprehend what it would be like.
Thus, we see that the fundamental makeup of the universe itself DEMANDS that we acknowledge the Triune God as its creator, since He created the universe in this manner and with these intricacies and interwovenness so that we would have to be focused on triune existence.
Further, then, if we look at each of these three elements, we see that they as well further break down into trinities as their fundamental basis.
SPACE - Has three mutually perpendicular directions, each of which require the other two for us to have meaningful existence. Imagine a world without one of the three. Say we had a universe with height and width, but not breadth. What would it be like? Like a drawing on paper? No, since anything we can make, no matter how thin, is absolutely three-dimensional. Paper has thickness, no matter how small. The ink line has depth, no matter how shallow. The smallest subatomic particle, the quark, still has extension in all three directions (just not very much compared to US). Our minds cannot truly and rationally conceive of a two-dimensional or a one-dimensional existence.
TIME - Time, which is essentially the relation of events to other events in a succession of events, perhaps can be relativistically sped up or slowed down (depending on your reference frame), perhaps can even be theoretically travelled backwards or forwards in at unusual rates, but it cannot exist without past, present, and future all existing. Imagine a time frame with past and present, but no future. Without the future, with nothing to progress to, past and present lose all meaningful relative value. Same with the absence of either of the other two parts. Unless you have all three aspects of that frame-relation, the whole existence of time as we know it breaks apart.
MATTER/ENERGY - The very fundamental existance of matter is that it, to the best of science's ability to determine, is made up of quarks. Progressing from molecules, we come to atoms. From atoms to protons, neutrons, and electrons. From these and other subatomic particles to quarks. Each and every subatomic particle is made up of one of various arrangements of three quarks. Protons are made of three quarks. So are neutrons, so are electrons, so are mesons, so are pions, etc. etc. The very building blocks of matter are arranged in trinities, and without these building blocks, existence as we know it simply is impossible.
All matter must exist in one of three forms: solid, liquid, or gas. Some may argue that plasma is a fourth state of matter, but a plasma is really just an ionised gas, which can exhibit strange behaviour under special circumstances (strong magnetic fields, etc.) There is no matter anywhere in the universe that does not exist, when viewed in relation to neighbouring atoms, as one of these three phases. Likewise, all matter can, depending on conditions, take any one of these three phases, or exist in two or three at equilibrium if under the proper conditions. We cannot imagine a substance which can exist in only two, but not the third, of these phases under all conceivable conditions. it simply doesn't exist.
Human Life and Makeup
The makeup of the human being cries out in favour of the trinitarian Creator. We are creatures with a trichotomous nature. We are body, soul, and spirit. The body is our physical existence, the matter that makes us up. The soul is our awareness and intellect, related to our mind, but not necessarily dependent just on the physical "brain" organ. The spirit is our immaterial existence, our motivating force and what maintains our life. Yet, without any one of these, we don't have true human existence as the full creatures God intended us to be.
Our DNA, the very artiface which determines our uniqueness, our person in all ways, and which God has said in the Bible that He has prepared and written in us before we were born, is fundamentally based up a triune existence. For the DNA molecule to even exist and function and replicate and propagate life, there must be all three parts of the DNA structure: the sugar backbone, the phosphate links which maintain the integrity of the backbone, and the nucleotide side chains which are attached to the backbone and which join the two helices of the DNA molecule together. Without any one of these three components, the DNA molecule does not exist as a functioning unit.
When DNA replicates, the two helices "unzip", coming apart so that copies can be transcripted and life can be propagated. This speaks to us even of Christ's temporary death and separation from the Father. Christ had to die and be separated so that new life could be obtained and given to those who trust in Him. After His work was finished, He was reunited. Yet, just as the two helices are never truly completely separated from each other, only portions at a time, so was Christ not completely separated from His Father, but only figuratively so and for a short time, yet God ordained for this to finalise His plan of redemption and new life.
Science, the faculty man has for investigating the creation which God has made, has opened to us the ability to see more than ever the testimony of His Triune nature which God has coded into the very fundamental elements of existence itself.