The Bible says God is “holy, holy, holy” (read Isaiah 6:1-7 and Revelation 4:5-11). Scripture is sufficient for us to understand the concept of the holiness of God while at the same time showing us that the full ramifications of God’s holiness are incomprehensible. If you want to start deeper contemplation upon the holiness of God, you may think to yourself where on earth do I even begin with such a God like this? And this is where we must realize that this is part of the problem. A twofold problem really:
1.) You can’t begin on earth. This is otherworldly.
It’s not merely that God’s holiness is inexhaustible. That’s certainly true, and that does convey part of the meaning of holiness. But there are other inexhaustible things out there. For example, start writing numbers until you come to the end. You won’t ever stop! Numbers never “end.” This is why we have the ∞ (infinity) symbol in math. Numbers are inexhaustible.
God’s holiness is inexhaustible as well, but it’s incomprehensible not just because we run out of words, but because every human word in any language is unsatisfactory. Even stringing words together won’t do the trick. The human language does not possess sufficiently adequate words to exhaustively describe or completely comprehend the holiness of God.
Numbers are inexhaustible, but when I say “infinity” you grasp the concept. But when it comes to God’s holiness, we are talking about something endlessly beyond that. It is beyond our language capabilities to comprehensively speak on it. The holiness of God breaks our puny words. The holiness of God is otherworldly. We can’t begin anywhere on earth because “holy” is beyond that. But this leads us to our second “problem”:
2.) Even though we can’t begin on earth, we must.
I am a created being and cannot get to a realm where I’m not bound by time, space, and material limitations, nor am I told to do this. I am a creature and reside in the creaturely realm. Humans cannot transcend time, space, or material limitations. And really, this is one of the first steps in attempting to grasp the reality of God’s transcendent holiness: The fact that we are not transcendently holy.
However, we need to be very careful here. We can’t dismiss the holiness of God by just telling ourselves it is other worldly and too far beyond us to meditate upon for a very important reason: Scripture. God has revealed Himself to us. The Holy has pulled back the curtain and invited us to peak in on who He really is. God has shown us who He is in His Word and through the person and work of His Son. No, we can’t exhaust God’s holiness, and our language will always fall short, but we can know what God intended for us to know about His holiness because the Bible is sufficient. As Andrew Rappaport has written: “God is greater than any human’s ability to understand Him. This does not mean that we cannot understanding anything about God, but that we can understand only that which He reveals to us.” 
The God who Speaks
In the Bible, God has communicated to us exactly what He wants us to know about Himself, and all that He wants us to know about Himself. And because God has given us His Word to see His resplendence, we are obligated to know it. It is our duty to know what God has revealed. Of course, as we dig deeper into the holiness of God we will see this is a glorious obligation for it is the very purpose for which we were created: to glorify God and enjoy Him forever. And that part of what God wants us to know about Himself is that His holiness is far beyond the capacities of the human mind, heart, or tongue.
Scripture is sufficient – it contains everything we need – for what God intended us to know about Himself, but don’t let that make you think God is “measurable”. Like, let’s just exhaust the topic of God’s holiness and move on to something better. No way! It is impossible to fully describe God’s holiness as it is His very nature.
In the purest sense of the word, holy, is basically a synonym for God. And God by definition is inexhaustible. Attempting to grasp God’s holiness stretches the English language, and at times shows us that language itself is woefully inadequate to comprehensively exhaust the subject. John Calvin put it this way: “[God’s] immensity surely ought to deter us from measuring him by our sense, while his spiritual nature forbids us to indulge in carnal or earthly speculation concerning him.” In other words, it is impossible for the finite creature to fully comprehend the infinite God. Or, to put it another way, He is the God of unspeakable holiness.
Let me illustrate it this way. Suppose one day you wanted to explain the intricacies of the human kidney to a toddler. What a challenge! Even the smartest of toddlers would not come close to fully understanding the total complexities of the human kidney. You could draw pictures and use words and concepts he or she understood, but at the end of the day you cannot make toddlers completely comprehend something that is so far beyond them.
In a way, we are the toddlers. God’s unspeakable holiness is like the concept of kidneys, and Scripture is His explanation to us. Of course, let’s be careful with analogies here. They always break down somewhere. The point is, God has spoken to us in “baby talk”; in a way that our finite toddler minds can grasp. Calvin put it this way: “For who is so devoid of intellect as not to understand that God, in so speaking, lisps with us as nurses are wont to do with little children?”
Therefore, we are fully responsible for knowing what God has revealed to us, but God has revealed Himself to us in such a way as to show us the reality of who He is: that we will spend an eternity in awe of Him and growing in our knowledge and delight of our triune God. It’s time to have a bigger view of God’s unspeakable holiness in our personal lives, in our homes, and in our churches.
 Andrew Rappaport. What Do We Believe?: A Systematic Theology of the Christian Faith (Jackson, NJ: Striving for Eternity Press, 2017), 74.
 John Calvin, Institutes of the Christian Religion (Bellingham, WA: Logos Bible Software, 1997), xiii, 1.
*This post is an adapted excerpt from a forthcoming book by Allen S. Nelson IV