Verse 20 “And Moses said unto the people, Fear not: for God is come to prove you, and that his fear may be before your faces, that ye sin not.”
God, in the same sentence says, “Fear not” and “that His fear (fear inspired by Him) may be before your faces.” It may sound like a contradiction, but the fact is that the Law of God should help put the fear of God into us that we sin not. By the Law is the knowledge of our sin, the awareness of our unacceptability with God, and our desire to please Him by receiving the only One who has kept God’s Law, Christ.