How can one differentiate between someone who has genuine faith and someone who simply has intellectual knowledge of the Bible?

Jesus Christ gives understanding of His Word, so it’s impossible to have the knowledge of Christ without Christ. It’s one of the gifts of the Holy Spirit.

1 John‬ 2‬:27‬ “But you have received the Holy Spirit, and he lives within you, so you don’t need anyone to teach you what is true. For the Spirit teaches you everything you need to know, and what he teaches is true—it is not a lie. So just as he has taught you, remain in fellowship with Christ.”

• Luke‬ 24‬:45‬ “Then he opened their minds to understand the Scriptures.”

The world is full of false teachers who use human wisdom, google search or AI to “explain things” to fool others that they know, what they don’t.

2 Peter‬ 3‬:15‬-16‬ “And remember, our Lord’s patience gives people time to be saved. This is what our beloved brother Paul also wrote to you with the wisdom God gave him— speaking of these things in all of his letters. Some of his comments are hard to understand, and those who are ignorant and unstable have twisted his letters to mean something quite different, just as they do with other parts of Scripture. And this will result in their destruction.”

You know them by their actions. But to be able to discern others is also one of the gifts of the Holy Spirit:

1 Corinthians‬ 12‬:10‬ “He gives one person the power to perform miracles, and another the ability to prophesy. He gives someone else the ability to discern whether a message is from the Spirit of God or from another spirit. Still another person is given the ability to speak in unknown languages, while another is given the ability to interpret what is being said.”

You cannot examine others if you have not examined yourself and repented. In other words: pull a log out of your own eye and you will be able to see. (Luke 6:42)

1 Corinthians‬ 2‬:13‬-16‬ “When we tell you these things, we do not use words that come from human wisdom. Instead, we speak words given to us by the Spirit, using the Spirit’s words to explain spiritual truths. But people who aren’t spiritual can’t receive these truths from God’s Spirit. It all sounds foolish to them and they can’t understand it, for only those who are spiritual can understand what the Spirit means. Those who are spiritual can evaluate all things, but they themselves cannot be evaluated by others. For, “Who can know the Lord’s thoughts? Who knows enough to teach him?” But we understand these things, for we have the mind of Christ.”

Learn more: Wolves in Sheep’s Clothing