Church of Jesus Christ of Latter day saints (Mormons)

Joseph Smith (1805-1844) founded 1830

Jesus' atonement plus the Laws and ordinances of the gospel

Members of their church

Triad - 3 gods.

Created being. The brother of the devil and of all people

Resurrected by grace, saved by doing works.

Yes

The Bible, Book of Mormon, Doctrine and Covenants, Pearl of Great Price