"to warn sb back"...

[szaroczek]

This is sort of confirmation of new adepts of devil's worshipers or something in... of course "Young Goodman Brown" :

"He could have well nigh sworn, that the shape of his own dead father beckoned him to advance, looking downward from a smoke-wreath, while a woman, with dim features of despair, threw out her hand to warn him back."

I guess this means something like, to "make him not to resign"..., right? Or just the opposite!

[5jj]

His father beckoned him to go forward, and the woman warned him to go back.

[SoothingDave]

I'm not sure what you mean by "resign."

In any event, the idea is that the one figure is motioning to him to advance, while the other is putting out a hand to say "move back." Warning him to move back.

[szaroczek]

What made me hesitate was the fact, that every creature gathered there seemed to be there in accordance with the main purpose of it... But there is really that word "while" which strongly suggests she really tried to worn him against proceeding in this ceremony.