"Oh, it is a great thing to be right with God, the soul in harmony with its Maker, so that, amid the contagion of evil example, which by its deceitful appearance would lure the soul from duty, angels may be sent to your rescue! But bear in mind, if you invite temptation, you will not have divine aid to keep you from being overcome. The three worthies endured the fiery furnace, for Jesus walked with them in the fiery flame. If they had, of themselves, walked into the fire, they would have been consumed. Thus will it be with you. If you do not walk deliberately into temptation, God will sustain you when the temptation comes. 3T 47.2"
"He answered and said, Lo, I see four men loose, walking in the midst of the fire, and they have no hurt; and the form of the fourth is like the Son of God."
The EGW passage directly references the story of the three worthies in the fiery furnace from Daniel 3. It uses the story as an illustration of God's protection when facing trials, but warns against deliberately seeking temptation.