misbeliever
nounUS /mɪsbɪˈlivɚ/ · UK /mɪsbɪˈliːvə/
Etymology From Middle English misbilevere, equivalent to misbelieve + -er.
1
Someone who holds a bad or wrong belief; a heretic, an unbeliever.
- We are placed in the country […] where we feare the menaces wherewith she threatneth all mis-beleevers, or follow her promises., II.12