The Nephites knew about and believed in Jesus 600 or so years before Jesus was born.
The Messiah cometh in six hundred years from the time that my father left Jerusalem ... his name shall be Jesus Christ, the Son of God. 2 Nephi 25:19
We believe in Christ ... we are made alive in Christ ... we talk of Christ, we rejoice in Christ, we preach of Christ, we prophesy of Christ. 25:24
And they began to call themselves "Christians" in 73 BCE.
And those who did belong to the church were faithful; yea, all those who were true believers in Christ took upon them, gladly, the name of Christ, or Christians as they were called, because of their belief in Christ who should come. Alma 46:15
