"The teacher of truth can impart effectively only that which he himself knows by experience. Christ taught the truth because He was the truth. His own thought, His character, His life experience, were embodied in His teaching. So with His servants; those who teach the word must make it their own by personal experience. They must know what it is to have Christ made unto them wisdom and righteousness and sanctification and redemption. Every minister of Christ and every teacher should be able to say with the beloved John, “The life was manifested, and we have seen it, and bear witness, and show unto you that eternal life, which was with the Father, and was manifested unto us.” 1 John 1:2 . CT 435.1"
"(For the life was manifested, and we have seen it, and bear witness, and shew unto you that eternal life, which was with the Father, and was manifested unto us;)"
Ellen White directly references 1 John 1:2 in this passage.