"The Gospel to all Countries Everywhere the light of truth is to shine forth, that hearts may be awakened and converted. In all countries the gospel is to be proclaimed. God's servants are to labor in places nigh and afar off, enlarging the cultivated portions of the vineyard, and going to the regions beyond. They are to work while the day lasts; for the night cometh, in which no man can work. Sinners are to be pointed to a Saviour uplifted on the cross, and from many voices is to be heard the invitation, “Behold the Lamb of God, which taketh away the sin of the world.” [ John 1:29 .] Churches are to be organized, and plans laid for work to be done by the members of the newly organized churches. As workers go forth filled with zeal, and with the love of God, the churches at home will be revived; for the success of the workers will be regarded as a subject of deep personal concern by every member of the church. GW 25"
"The next day John seeth Jesus coming unto him, and saith, Behold the Lamb of God, which taketh away the sin of the world."
Ellen White directly references John 1:29 in this passage.