Does knowledge include spiritual understanding?
Yes, knowledge includes spiritual understanding. The context states that knowledge is not limited to the secular world but also extends into the spiritual area and the understanding of God's Word. It notes a greater understanding of the Scriptures in these last days, as God reveals what was once secret.
Les explains that while there is an explosion of secular knowledge, there is also a greater understanding of the Scriptures in these last days. He points to Deuteronomy 29:29, that the secret things belong unto the Lord our God, and says God has kept things secret but is now revealing them as we approach the end of the age. Therefore knowledge is not just limited to the secular world; it also includes the spiritual and the understanding of God's Word.