Manchurian candidates exist in the church also. In fact, some of the vilest forms of betrayal occur in the church and among individuals who believe in God.
Manchurian candidates in the church are not uniquely members of the antichrist's army. Some of them are members of God's army. Some of them are members of Satan's army. And some have their personal armies.
When called to action, members of Satan's army are expected to instantly obey. The same is true for members of the antichrist's army. They have no choice and no free will. God's army has a choice, they can choose whether or not they will obey. But there are consequences for disobedience--consequences that can result in being excluded from the Kingdom of God.
When called to action, free men and women of God should say: "Here I am, Lord. Is it I, Lord? I have heard you calling in the night. I will go, Lord, if you lead me. I will hold your people in my heart."