They will be held accountable.
MATTHEW 18:6
“If anyone causes one of these little ones—those who believe in me—to stumble, it would be better for them to have a large millstone hung around their neck and to be drowned in the depths of the sea.
You seem all too ready to condemn your brother for accepting what The Father has given. Put your Faith in Him, not what you have been told and shown by man.
He said it. He meant it. It is up to you to believe it.
Be filled with The Fathers Love!