"A concealed golden wedge and a Babylonish garment troubled the entire camp of Israel. The frown of God was brought upon the people because of the sin of one man. Thousands were slain upon the field of battle because God would not bless and prosper a people among whom there was even one sinner, one who had transgressed His word. This sinner was not in holy office, yet a jealous God could not go forth to battle with the armies of Israel while these concealed sins were in the camp. 3T 239.1"
"When I saw among the spoils a goodly Babylonish garment, and two hundred shekels of silver, and a wedge of gold of fifty shekels weight, then I coveted them, and took them; and, behold, they are hid in the earth in the midst of my tent, and the silver under it."
The EGW passage directly references the story of Achan in Joshua 7, including the 'Babylonish garment' and 'wedge of gold,' and draws a parallel.
"Notwithstanding the apostle's warning is before us to “abstain from all appearance of evil,” some persist in pursuing a course unbecoming Christians. God requires His people to be holy, to keep themselves separate from the works of darkness, to be pure in heart and life, and unspotted from the world. The children of God, by faith in Christ, are His chosen people; and when they stand upon the holy ground of Bible truth they will be saved from fellowship with the unfruitful works of darkness. 3T 239.2"
"Abstain from all appearance of evil."
The EGW passage directly quotes 1 Thessalonians 5:22.