"Arriving at Salamis, the apostles “preached the word of God in the synagogues of the Jews.... And when they had gone through the isle unto Paphos, they found a certain sorcerer, a false prophet, a Jew, whose name was Bar-Jesus: which was with the deputy of the country, Sergius Paulus, a prudent man; who called for Barnabas and Saul, and desired to hear the word of God. But Elymas the sorcerer (for so is his name by interpretation) withstood them, seeking to turn away the deputy from the faith.” AA 167.1"
"And when they were at Salamis, they preached the word of God in the synagogues of the Jews: and they had also John to their minister."
EGW directly quotes and paraphrases Acts 13:5, recounting the events in Salamis. This is a clear and direct reference.
"Not without a struggle does Satan allow the kingdom of God to be built up in the earth. The forces of evil are engaged in unceasing warfare against the agencies appointed for the spread of the gospel, and these powers of darkness are especially active when the truth is proclaimed before men of repute and sterling integrity. Thus it was when Sergius Paulus, the deputy of Cyprus, was listening to the gospel message. The deputy had sent for the apostles, that he might be instructed in the message they had come to bear, and now the forces of evil, working through the sorcerer Elymas, sought with their baleful suggestions to turn him from the faith and so thwart the purpose of God. AA 167.2"
"For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places."
EGW describes the opposition faced by the apostles from Elymas, interpreting it as a manifestation of Satan's resistance to the spread of the gospel. This aligns with the broader theme in Ephesians 6:12 about spiritual warfare against powers of darkness, even though it's not a direct quote or explicit allusion.