A.B. Simpson emphasizes the profound impact of speech as a defining characteristic of humanity, asserting that the way we communicate reveals our true character. He warns that failing to control one's tongue indicates an unsanctified spirit, while mastering our words signifies spiritual maturity and alignment with the Holy Spirit. Simpson illustrates the consequences of careless speech through the example of Moses, whose unguarded words cost him the opportunity to enter the Promised Land. He concludes that our words have eternal significance, as they can justify or condemn us before God.

Speech is one of the supreme distinctions between man and the lower animals. The power of expressing thought in articulation and written language is one of the high prerogatives of rational beings. A man's conversation is the real test of his character and if any man among you seem to be religious, and bridleth not his tongue, but deceiveth his own heart, this man's religion is vain (James 1:26). An unbridled tongue is a sure sign of an unsanctified spirit. On the other hand, if any man offend not in word, the same is a perfect man, and able also to bridle the whole body. It is a sign that he is under the government of his conscience, his will and the Holy Spirit. This is a most heart-searching test. It was a foolish word that lost Moses the Land of Promise. He would have taken it back if he could have, but it was too late. Though he was taken to heaven, he could not lead Israel into the promised land. Many men and women of great potential ruin their whole lives by an uncontrolled tongue. It settles our character and influence here. How much more in the sight of Him who has said, By thy words thou shalt be justified and by thy words thou shalt be condemned (Matthew 12:37).