From the current priesthood/relief society manual: “Knowledge is necessary to life and godliness."

True, knowledge is necessary, as it is the fruit (or part) of the tree of faith. God possesses knowledge, so we must, also.

"Woe unto you priests and divines who preach that knowledge is not necessary unto life and salvation."

I don’t know what the priests of Joseph’s day were preaching, but it may be that Joseph was combating or contradicting the notion that we have a Bible and need no more Bible (no more revelatory knowledge.)

"Take away Apostles, etc., take away knowledge, and you will find yourselves worthy of the damnation of hell. Knowledge is revelation."

This is the key to understanding Joseph’s words. Revelation is the word of God, or the seed of faith. Joseph is not talking about just any knowledge, he is talking about revelatory knowledge, which is the type that comes from the seed of faith.

"Hear, all ye brethren, this grand key: knowledge is the power of God unto salvation.”13

True, revelatory knowledge is, indeed, the power of God, as revelatory knowledge is the seed of faith, which, when planted, produces faith, which in turn produces agency (power) unto salvation.

“Knowledge does away with darkness, suspense and doubt; for these cannot exist where knowledge is. …"

Again, we must qualify Joseph’s words, as the devil possesses knowledge, yet is in darkness. Joseph, again, is talking only of revelatory knowledge, or the word of God planted in the heart of man, which is the seed of faith.

"In knowledge there is power. God has more power than all other beings, because He has greater knowledge; and hence He knows how to subject all other beings to Him. He has power over all.”14

Joseph is talking here of revelatory knowledge. God has more agency (see The role of agency in political systems and The faith of God, part ten: the relationship of faith to agency (power)) as he has more revelatory knowledge, which comes of faith. In other words, the faith of God is absolute, which produces, among other things, absolute agency and absolute knowledge. Therefore, he cannot be defeated, overcome or overpowered, only matched by other absolute beings in possession of all things in their fullness.

“As far as we degenerate from God, we descend to the devil and lose knowledge, and without knowledge we cannot be saved, and while our hearts are filled with evil, and we are studying evil, there is no room in our hearts for good, or studying good. Is not God good? Then you be good; if He is faithful, then you be faithful. Add to your faith virtue, to virtue knowledge, and seek for every good thing [see 2 Peter 1:5]."

It is instructive that Joseph begins the list with faith, then virtue and lastly knowledge. He is talking about the growing seed of faith which eventually produces the fruit of knowledge.

“… A man is saved no faster than he gets knowledge, for if he does not get knowledge, he will be brought into captivity by some evil power in the other world, as evil spirits will have more knowledge, and consequently more power than many men who are on the earth."

Faith must be confirmed, otherwise we lose it and fall. Faith is confirmed by knowledge (signs/witnesses). (See D&C 5: 32; Ether 12: 6 and Mormon 9: 24-25.)

"Hence it needs revelation to assist us, and give us knowledge of the things of God.”15

Joseph Smith taught the following in April 1843, later recorded in Doctrine and Covenants 130:18–19: “Whatever principle of intelligence we attain unto in this life, it will rise with us in the resurrection. And if a person gains more knowledge and intelligence in this life through his diligence and obedience than another, he will have so much the advantage in the world to come.”16

This is true, however, again, we must understand that these verses are talking of revelatory knowledge, not just any knowledge. In other words, whoever possesses more of the word of God (revelatory knowledge) planted in their hearts will have more advantage, not that a plumber who knows how to fix pipes will have more advantage than I, who am not a plumber.

To summarize, Joseph wasn’t saying that knowledge alone saves, or even that we are saved by knowledge, but that you cannot eliminate the fruit of the tree of life, which is knowledge, and expect to be saved. He is also only talking about revelatory knowledge, which comes of faith.

“Knowledge does away with darkness, suspense and doubt; for these cannot exist where knowledge is. … In knowledge there is power. God has more power than all other beings, because He has greater knowledge; and hence He knows how to subject all other beings to Him. He has power over all.”14

“As far as we degenerate from God, we descend to the devil and lose knowledge, and without knowledge we cannot be saved, and while our hearts are filled with evil, and we are studying evil, there is no room in our hearts for good, or studying good. Is not God good? Then you be good; if He is faithful, then you be faithful. Add to your faith virtue, to virtue knowledge, and seek for every good thing [see 2 Peter 1:5].

“… A man is saved no faster than he gets knowledge, for if he does not get knowledge, he will be brought into captivity by some evil power in the other world, as evil spirits will have more knowledge, and consequently more power than many men who are on the earth. Hence it needs revelation to assist us, and give us knowledge of the things of God.”15

Joseph Smith taught the following in April 1843, later recorded in Doctrine and Covenants 130:18–19: “Whatever principle of intelligence we attain unto in this life, it will rise with us in the resurrection. And if a person gains more knowledge and intelligence in this life through his diligence and obedience than another, he will have so much the advantage in the world to come.”16