The first commandment forbids our denying of the true God and serving of other gods. To do so is a sin of commission. It requires that we know, acknowledge, love, and serve the true God above all else. To not do so is a sin of omission.

The first commandment is foundational: it is called the great commandment. It describes the chief duty of man -to know, love, serve, and glorify his Creator. Jesus taught, "Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind. This is the first and great commandment" (Matthew 22:37-38)

The first commandment forbids atheism. Atheism denies God His rightful place. It refuses to acknowledge God's existence and fails to love and serve Him as Lord. Atheism can be practiced in blatant, subtle, or practical ways. The following examples illustrate each; all break God's first commandment.

The famous German mathematician, Athanasius Kircher, having an astronomer friend who denied the existence of God, used the following approach to convince him of his error.

Expecting him to visit in the near future, he purchased an expensive, very-detailed globe of the starry heavens which he placed in a conspicuous place in the room in which they would be visiting. Upon entering the room, the astronomer's eye was immediately drawn to the globe. After examining it carefully and admiring its detail and accuracy, he asked Mr. Kircher if he knew who had constructed it.