There was a fair bit of established orthodox doctrine laid down between 100-400 CE. Christian groups that follow this are generally considered Christian by each

There was a fair bit of established orthodox doctrine laid down between 100-400 CE. Christian groups that follow this are generally considered Christian by each by each other. Mormonism deviates significantly from orthodox doctrine, so it is considered a heretical sect by Christians. For analogy, comparing Mormonism to Christianity is sort of like comparing Chrome to Konqueror.