"Elisha's life after uniting with Elijah was not without temptations. Trials he had in abundance; but in every emergency he relied on God. He was tempted to think of the home that he had left, but to this temptation he gave no heed. Having put his hand to the plow, he was resolved not to turn back, and through test and trial he proved true to his trust. PK 222.3"
"And Jesus said unto him, No man, having put his hand to the plough, and looking back, is fit for the kingdom of God."
EGW directly alludes to Luke 9:62, using the imagery of putting one's hand to the plow and not looking back to illustrate Elisha's commitment.
"we have seen and heard declare we unto you.” 1 John 1:1-3 . Young, inexperienced workers should be trained by actual labor in connection with these experienced servants of God. Thus they will learn how to bear burdens. PK 222.4"
"That which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked upon, and our hands have handled, of the Word of life; (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;) That which we have seen and heard declare we unto you, that ye also may have fellowship with us: and truly our fellowship is with the Father, and with his Son Jesus Christ."
Ellen White directly references 1 John 1:1-3 in this passage.