Many of our critics have often quoted Galatians 1:6-8 as a proof text that the teachings of the LDS Church equals another gospel. In my experience, often this passage is quoted and the interpretation is generally as follows:
1) Paul warned about the possibility of "another" gospel being preached by an "angel."
2) Mormons believe that the angel Moroni (among others) came and "restored" the gospel.
3) Mormonism is "another" gospel.
There is, of course, a logical fallacy here (high five to the first person who points it out by name!). Besides the logical fallacy, what do our critics do with Revelation 14:6?
6 And I saw another angel fly in the midst of heaven, having the everlasting gospel to preach unto them that dwell on the earth, and to every nation, and kindred, and tongue, and people,
Clearly there is a difference between "another" gospel and the "everlasting" gospel. So, can an angel (theoretically and biblically) come to preach the gospel to people on earth? I'd say not only can it happen, but it was predicted that it would happen.
I submit that Paul's warning in Galatians only shows that the apostasy was well underway then and he knew it. Thus the need in the last days for an angel to come and reverse the work of the devil ("And it was given unto him to make war with the saints, and to overcome them: and power was given him over all kindreds, and tongues, and nations" [Revelation 13:7].) by restoring the everlasting gospel to "every nation, and kindred, and tongue, and people."