Adoptionism and salvation

Perhaps, this was why, in response to arguments like these, the fourth General Council of Chalcedon (451 CE) supplemented a new definition to the Nicene Creed. The following statement refuted such claim that Christ’s divinity and humanity were transformed into something else:

We all with one voice confess our Lord Jesus Christ one and the same Son, at once complete in Godhead and complete in manhood, truly God and truly man…… Acknowledged in two natures, without confusion, without change, without division, or without separation; the distinction of natures being in no way abolished because of the union, but rather the characteristic property of each nature being preserved, and coming together to form one person. (Shelley 145-6).

Regarding the issue of salvation, that is rather a complicated one. Can one simply be saved just by "believing" in Jesus? Or does it matter which and what kind of Jesus he/she believes and how he/she believes? James 2:19 says, You believe that God is one; you do well. Even the demons believe—and shudder.