Human beings use language to communicate, and this is as true when they are doing theology as when they are speaking about other topics. For centuries, people took it for granted that human language was an adequate vehicle for speaking about God, but in the twentieth century, things began to change. Philosophers of religion and certain theologians began to question whether human speech could convey truth about our Creator. This led to a full-scale rejection of traditional ways of talking about God and His attributes at seminaries that had capitulated to theological modernism. Since human language was thought to be incapable of saying anything definitive about the Lord, thinkers began to view traditional theological categories with great skepticism. Moreover, theology became increasingly seen as a science in which we do our best to say something about God as we imagine Him, not as a discipline in which we do our best to understand God as He reveals Himself. Liberal theologians such as Paul Tillich eschewed the personal language about God found in Scripture in favor of impersonal designations such as God as the “ground of all being,” and even then, these designations were virtually emptied of whatever biblical content that might have remained.
As finite creatures, we use language that has limits when it comes to portraying God’s attributes. But these limits do not make human speech worthless as an instrument of speaking truth about God. Since God made us in His image (Gen. 1:26–27), He has made us able to communicate in true and meaningful ways when we talk about Him.
Traditionally, theologians have said that human language about God is analogical language. To speak analogically is to use the same word to describe two different things, and yet the word is not used in exactly the same way for each thing under discussion. For example, we can speak of “good students” and “good dogs,” meaning that both students and dogs can be obedient. However, the obedience of students and the obedience of dogs, though similar, is of a different order. Both may obey commands, but we look for students to (eventually) obey as the result of sound moral reasoning and not merely out of a basic system of rewards and punishment.
When David refers to God as a “rock” in Psalm 18:2, he is speaking analogically. He is saying that like a rock, the Lord is firm and unshakable. God is like a rock in that way, but He is not literally a stone or a formation of minerals.