An excellent question.
If you are a Christian, you undoubtedly believe (as I do) that Jesus Christ was and is God and therefore unchangeable.
Nevertheless, Jesus clearly changed. He was born as a baby and grew to manhood. During that time, "Jesus increased in wisdom and stature, and in favor with God and man." (Luke 2:52) Eventually, he suffered death on the cross, rose again the third day, and ascended into heaven.
Hence, Jesus Christ is an unchangeable being who changed. How do we resolve this apparent contradiction?
I believe that the key is the doctrine that God is love (1 John 4:16). Jesus has always been perfect in his love for God the Father and for his fellow men. Likewise, he has always been perfect in faith, hope, mercy, and justice. Although he was "in all points tempted like as we are, yet [he was] without sin." (Hebrews 4:10). In short, he has always been completely good.
Jesus Christ changed physically, but the Godly attributes of his character do not change.
Hence, Jesus Christ is an unchangeable being who changed. How do we resolve this apparent contradiction?
Through the theology of the Holy Trinity, hypostatic union, divine essence, etc.
It's quite far from LDS teaching of course, but it's complete. You could look for "An Exact Exposition of the Orthodox Faith" by St John Damascene for the long form.
On another tack, it is pretty much universal in all religions that God is infinite in being (The Doctrine of the Holy Trinity also holds this). This of course is what makes it monotheistic.
I believe we've touched this point before, but LDS, I think you would agree, is polytheistic, multiple Gods, if as others have stated (some) men are destined to become God(s).