Although we might think of many ways that the Holy Spirit works within human beings to reveal truth about God, we’ll focus on two. First, we’ll explore what theologians have traditionally called “illumination.”

When we speak of the illumination of the Holy Spirit, we’re referring to a divine gift of understanding that God gives to believers, and even to unbelievers. When the Holy Spirit illumines a person’s mind, he gives that person an ability or knowledge that the person previously lacked. One of the clearest examples of illumination can be found in Matthew 16:15-17, where we read the following account:

[Jesus] said to them, “But who do you say that I am?” Simon Peter replied, “You are the Christ, the Son of the living God.” And Jesus answered him, “Blessed are you, Simon Bar-Jonah! For flesh and blood has not revealed this to you, but my Father who is in heaven.”

Simon Peter didn’t figure out on his own that Jesus was the Christ, nor did he learn it from other people. Instead, God directly revealed that knowledge to Peter. Paul addressed the issue of the illumination of believers rather directly when he wrote these words:

It has been granted to you that for the sake of Christ you should … believe in him. (Philippians 1:29)

The Greek word here translated “granted” is from the verb charizomai, meaning “given freely.” Paul’s point is not that the Philippians were granted the opportunity to believe, but rather, that God gave to them, as a free gift, their very faith in Jesus. Interestingly, the Bible also teaches us that God illumines even unbelievers. Listen to Paul’s words in Romans 2:14-15:

When Gentiles, who do not have the law, by nature do what the law requires, they … show that the work of the law is written on their hearts … and their conflicting thoughts accuse or even excuse them.

In other words, God implants in every human being, even in unbelievers, a basic knowledge of his law. We all instinctively know that certain things are right and wrong. And our consciences bear witness to this fact.

Second, the Holy Spirit also provides what has often been called “inward leading.” Inward leading — as opposed to illumination, which is primarily cognitive — tends to be more emotive and intuitive. It is one of the most common ways in which the Holy Spirit works within individuals to reveal truth about God’s character. We see inward leading displayed clearly in things like our individual consciences, as well as in our often-indescribable feelings that God would have us take a particular course of action. Paul referred to this elusive inward leading in Philippians 2:13:

It is God who works in you, both to will and to work for his good pleasure.

Notice that Paul was not speaking here of what we know or believe, but rather of what we will or desire, of what motivates our actions. This, too, is a form of revelation because it communicates impressions and intuitions about God’s character to us. And just as with all forms of existential revelation, because it reveals God’s character, it is a binding standard that we must obey and to which we must conform.