"“Let us reject this decree,” said the princes. “In matters of conscience the majority has no power.” The deputies declared: “It is to the decree of 1526 that we are indebted for the peace that the empire enjoys: its abolition would fill Germany with troubles and divisions. The Diet is incompetent to do more than preserve religious liberty until the council meets.”— Ibid., b. 13, ch. 5. To protect liberty of conscience is the duty of the state, and this is the limit of its authority in matters of religion. Every secular government that attempts to regulate or enforce religious observances by civil authority is sacrificing the very principle for which the evangelical Christian so nobly struggled. GC 201.1"
"They say unto him, Cesar’s. Then saith he unto them, Render therefore unto Cesar the things which are Cesar’s; and unto God the things that are God’s."
While Matthew 22:21 is about rendering to Caesar what is Caesar's and to God what is God's, the EGW quote discusses the limits of state authority in matters of religion and liberty of conscience. The connection is that both passages address the relationship between secular authority and religious obligation, but the EGW quote is a specific application of the principle of separating secular and religious domains. Confidence adjusted down because the connection is not as direct as it could be.
"King Ferdinand, the emperor's representative at the Diet, saw that the decree would cause serious divisions unless the princes could be induced to accept and sustain it. He therefore tried the art of persuasion, well knowing that to employ force with such men would only render them the more determined. He “begged the princes to accept the decree, assuring them that the emperor would be exceedingly pleased with them.” But these faithful men acknowledged an authority above that of earthly rulers, and they answered calmly: “We will obey the emperor in everything that may contribute to maintain peace and the honor of God.”— Ibid., b. 13, ch. 5. GC 201.3"
"Then Peter and the other apostles answered and said, We ought to obey God rather than men."
The EGW quote directly echoes the principle of obeying God rather than men, as exemplified in Acts 5:29. The princes' refusal to obey the emperor when it conflicted with their conscience aligns perfectly with Peter's statement.