This celebrated maxim captures the essence of the dichotomy between the telestial and the celestial manner of living. Jacob must surely have remembered the words of his father Lehi:
Wherefore, men are free according to the flesh; and all things are given them which are expedient unto man. And they are free to choose liberty and eternal life, through the great Mediator of all men, or to choose captivity and death, according to the captivity and power of the devil; for he seeketh that all men might be miserable like unto himself.
And now, my sons, I would that ye should look to the great Mediator, and hearken unto his great commandments; and be faithful unto his words, and choose eternal life, according to the will of his Holy Spirit;
And not choose eternal death, according to the will of the flesh and the evil which is therein, which giveth the spirit of the devil power to captivate, to bring you down to hell, that he may reign over you in his own kingdom. (2 Nephi 2:27–29)
The lesson is plain and clear: Think good thoughts, do good deeds, love God, and keep the commandments.