I have made a covenant with God that I can take on His name, which is Christ, if I always obey His commandments. This concept is taught in Mosiah 5:7-8:
“And now, because of the covenant which ye have made ye shall be called the children of Christ, his sons, and his daughters; for behold, this day he hath spiritually begotten you; for ye say that your hearts are changed through faith on his name; therefore, ye are born of him and have become his sons and his daughters.
And under his head ye are made free, and there is no other head whereby ye can be made free. There is no other name given whereby salvation cometh; therefore, I would that ye should take upon you the name of Christ, all you that have entered into the covenant with God that ye should be obedient unto the end of your lives.”
And, as in all covenants, I have received a promise, if I am true and faithful to this covenant:
“Therefore, I would that ye should be steadfast and immovable, always abounding in good works, that Christ, the Lord God Omnipotent, may seal you his, that you may be brought to heaven, that ye may have everlasting salvation and eternal life, through the wisdom, and power, and justice, and mercy of him who created all things, in heaven and in earth, who is God above all, Amen.” (Mosiah 5:15).
This is what I previously wrote after reading Mosiah 5: Being Good Christians