Christians believe in the Bible, and nowhere in the Bible does it talk about spirit children, or Jesus being the first born of the spirit children, or wearing holy undergarments in the temple, or salvation being based on your own good works rather than on Christ's work of salvation for us, or about a second "following" or Israel in North America, or Joseph Smith, or baptising dead relatives...See what I mean?
I think there are probably many Mormons who believe in Christ as their Savior, and are otherwise deceived in their faith of Mormonism. God will judge fairly, and probably many sincere (but deceived) people of non-Christian faith may be judged to be "faithful" to Christ and therefore enjoy Heaven. I'm not trying to determine who these people are and aren't. But basic theology says you can't maintain the integrity of a religion unless you have some "non-negitiable" points of truth. Otherwise the religion doesn't mean much. Mormonism has a lot of conflicts with Christian theology. It doesn't fit in. You really can't argue with that if you compare the two. May God bless you as you search for him and for truth.
nowhere in the Bible does it talk about spirit children
Jer 1:5 "Before I formed thee in the belly I knew thee; and before thou camest forth out of the womb I sanctified thee, and I ordained thee a prophet unto the nations."
wearing holy undergarments in the temple
Perhaps not specifically, but as for the importance and sacred nature of temples, there are plenty of references to them in the Old Testament.
salvation being based on your own good works rather than on Christ's work of salvation for us
James 2:26 "For as the body without the spirit is dead, so faith without works is dead also."
second "following"
Not sure what you mean by that
Joseph Smith
He's not mentioned by name, but here's a scripture about the coming forth of the Book of Mormon
Ezek. 37: 19 "Say unto them, Thus saith the Lord GOD; Behold, I will take the stick of Joseph, which is in the hand of Ephraim, and the tribes of Israel his fellows, and will put them with him, even with the stick of Judah, and make them one stick, and they shall be one in mine hand."
The stick of Judah is the Bible, the stick of Joseph is the Book of Mormon. The people who wrote the plates where of the tribe of Joseph. (The New and Old Testaments were written by the tribe of Judah.)
baptising dead relatives
1 Cor. 15:29 "Else what shall they do which are baptized for the dead, if the dead rise not at all? why are they then baptized for the dead?
Mormonism has a lot of conflicts with Christian theology
Not from what I see.
Unfortunately, however the Mormons are way out of line. They have created a new religion that does NOT line up with the OT prophets and the faith practices of Jesus.
For example?