"The eight-hour system finds no place in the program of the minister of God. He must hold himself in readiness for service at any hour. He must keep up his life and energy; for if he is dull and languid, he cannot exert a saving influence. If he occupies a position of responsibility, he must be prepared to attend board and council meetings, spending hours in brain- and nerve-taxing labor, planning for the advancement of the cause. Work of this kind is a heavy tax on mind and body. GW 451.1"
"No man that warreth entangleth himself with the affairs of this life; that he may please him who hath chosen him to be a soldier."
Both passages discuss the dedication required of those serving God. 2 Timothy 2:4 states that a soldier does not entangle himself with worldly affairs, while EGW emphasizes the minister's constant readiness and heavy workload. The connection lies in the theme of commitment and sacrifice, though the contexts differ slightly.
"Isaiah, he hears the voice of the Lord saying, “Whom shall I send, and who will go for us?” he responds, “Here am I; send me.” [ Isaiah 6:8 .] He cannot say, I am my own; I will do what I please with my time. No one who has given his life to God's work as His minister, lives for self. His work is to follow Christ, to be a willing agent and co-worker with the Master, receiving His Spirit day by day, and working as the Saviour worked, neither failing nor being discouraged. He is chosen of God as a faithful instrument to promote missionary work in all lands, and he must ponder well the path he follows. GW 451.2"
"Also I heard the voice of the Lord, saying, Whom shall I send, and who will go for us? Then said I, Here am I; send me."
Ellen White directly references Isaiah 6:8 in this passage.
"And he said to them all, If any man will come after me, let him deny himself, and take up his cross daily, and follow me."
EGW uses Isaiah 6:8 as an example of willingness to serve God and connects it to the idea of self-denial and following Christ. This aligns with Luke 9:23, which calls for self-denial and following Jesus. The connection is based on the principle of sacrificing personal desires for God's work.
"Those who have never carried the burden of such work, and who suppose that the Lord's chosen and faithful ministers have an easy time, should bear in mind that sentinels for God are on duty constantly. Their labor is not measured by hours. When their accounts are audited, if selfish men, with voice or stroke of pen, limit them unduly in their wages, a great wrong is done. GW 451.3"
"Even so hath the Lord ordained that they which preach the gospel should live of the gospel."
The EGW quote directly addresses the principle that those who minister should be fairly compensated, echoing the sentiment in 1 Corinthians 9:14 that those who preach the gospel should live of the gospel.