Thank you James, for your testimony of the truthfulness of the word of God, of salvation through Christ....and the differences in the LDS Church and Christian belief.
You are blessed to have found saving faith by age 12 after coming out of Mormonism. It took me many years more than that. Many others are lost to disbelief entirely. Mormonism does such an adequate job of attacking the inerrancy of the Bible and the omnipotence, and unchanging nature of God, that many who leave Mormonism turn into atheists or agnostics.
This type of argument is ultimately vain, as you well know. So long as the definition of a Christian is controlled by extra-Biblical philosophies or sources, there is no standard on which to measure each side of the debate. Mormons use an extra-Biblical standard based on what they claim is modern-day revelation. Most others base their definition on ecumenical councils centuries after the death of the Savior. If each holds to its definition, then all others are ipso facto “non-Christian”. (BibChr holds to the definition, apparently, of solely grace, solely Bible, which would seem to exclude the Catholic Church which believes in works and tradition. See how this kind of debate gets us nowhere.)
It seems a more worthy argument is to accept the standard of the discipleship that one follows the teachings of their professed master. However, this kind of argument hits many “acceptable” Christians full in the face because of the great diversity among practices such as baptism, priesthood authority, church organization, offices in the church, confession, treatment of homosexuality and extra-marital sexual relations, tithing, etc., etc. So that is also ultimately a difficult argument.
Best yet, let’s leave the definition to the Savior who will recognize all His people when He comes to reign on the earth again.
Color Country, regarding your tag line, consider Isaiah 55:8-9. Just a suggestion.