"The Saviour has given His precious life in order to establish a church capable of ministering to the suffering, the sorrowful, and the tempted. A company of believers may be poor, uneducated, and unknown; yet in Christ they may do a work in the home, in the community, and even in “the regions beyond,” whose results shall be as far-reaching as eternity. MH 106.4"
"Now ye are the body of Christ, and members in particular."
The EGW passage describes the church as an instrument for ministering to the suffering, while 1 Corinthians 12:27 describes believers as the body of Christ. The connection lies in the idea that the church, as the body of Christ, is meant to continue His work of compassion and service. The 'regions beyond' also suggests the far-reaching influence of the church, similar to the interconnectedness of the body.
"“All power is given unto Me in heaven and in earth. Go ye therefore, and teach all nations.” “Go ye into all the world, and preach the gospel to every creature.” Matthew 28:18, 19 ; Mark 16:15 . MH 106.6"
"And he said unto them, Go ye into all the world, and preach the gospel to every creature."
Ellen White directly references Mark 16:15 in this passage.