The Lord revealed in D&C 88 that the light of Christ is "in all things" and "giveth life to all things, which is the law by which all things are governed" in heaven and on earth. (See verses 6-13.)
"As part of life itself," taught the late Elder Bruce R. McConkie of the Quorum of the Twelve, "all mortals are endowed with a heavenly gift called the light of Christ. This divine endowment manifests to us the difference between good and evil. We do not need to be taught what is right and wrong. This knowledge is bred in our bones; it is hereditary; it is innate, inborn, and intuitional in nature. Call it conscience, if you will; say that it is a divine inheritance from a Divine Parent; identify it as a spark of divinity sent by Deity to fire the soul with the flames of righteousness; call it the Spirit of Christ - it has many names. But what counts is that it is real. It is
the true light that lighteth every man that cometh into the world.' (D&C 93:2.) Of it Mormon said:The Spirit of Christ is given to every man, that he may know good from evil.' (Moro. 7:16.)"In a revelation to Joseph Smith the Lord called it `the Spirit of Jesus Christ and the Spirit giveth light to every man that cometh into the world."
All receive a divine inheritance at birth. It is a free gift as far as any act performed in mortality is concerned. `The Spirit enlighteneth every man through the world, that hearkeneth to the voice of the Spirit. And every one that hearkeneth to the voice of the Spirit cometh unto God, even the Father." (D&C 84:45-47.)