"Know that these things are true"

1. Hel. 7: 29
     29 Behold now, I do not say that these things shall be, of myself, because it is not of myself that I know these things; but behold, I know that these things are true because the Lord God has made them known unto me, therefore I testify that they shall be.
2. Ether 4: 11
     11 But he that believeth these things which I have spoken, him will I visit with the manifestations of my Spirit, and he shall know and bear record. For because of my Spirit he shall know that these things are true; for it persuadeth men to do good.
3. D&C 20: 35
     35 And we know that these things are true and according to the revelations of John, neither adding to, nor diminishing from the prophecy of his book, the holy scriptures, or the revelations of God which shall come hereafter by the gift and power of the Holy Ghost, the voice of God, or the ministering of angels.