"If all who have influence felt the necessity of co-operation and would seek to answer the prayer of Christ, that they may be one as He is one with the Father, the cause of present truth would be a power upon this coast. But the people of God are asleep, and do not see the wants of the cause for this time. They do not feel the importance of concentrated action. Satan is ever seeking to divide the faith and hearts of God's people. He well knows that union is their strength, and division their weakness. It is important and essential that all of Christ's followers understand Satan's devices and with a united front meet his attacks and vanquish him. They need to make continual efforts to press together even if it be at some sacrifice to themselves. 3T 434.4"
"That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us: that the world may believe that thou hast sent me."
EGW directly references and quotes John 17:21, emphasizing the importance of unity among believers as Christ is one with the Father. This is a clear and direct allusion.