In Isaiah 7:14, we read “Therefore the Lord himself shall give you a sign; Behold, a virgin shall conceive, and bear a son, and shall call his name Immanuel.”

The name ‘Immanuel’ means ‘God with us’.

When Jesus Christ, “the only begotten of the Father” came into the world, “the Word was made flesh, and dwelt among us” (John 1:14).

From His Father, Jesus inherited immortality and Godhood. From His mother Mary, the virgin mentioned by Isaiah, He inherited mortality and the ability to be truly ‘with us’; subject to pain, sickness, temptation (though he never succumbed) and death.

Elder Mark E Petersen commented: “How appropriate that name, for He was God, and indeed He came into the world to be with us. “God with us”! This He was in fact. He was deity before he was born into mortality, and He was His divine self while on the earth.”

Even before being made flesh, Jehovah was ‘with’ His faithful followers. King David taught his son Solomon: “Be strong and of good courage… fear not, nor be dismayed: for the Lord God, even my God, will be with thee; he will not fail thee, nor forsake thee” (1 Chronicles 28:20)

Jesus, Immanuel, continues to be ‘with us’. He taught His disciples “For where two or three are gathered together in my name, there am I in the midst of them” (Matthew 18:20). To Joseph Smith, he said “I am the Lord thy God, and will be even unto the end of the world, and through all eternity” and to His followers, he promises “And behold, and lo, I am with the faithful always. Even so. Amen.” (D&C 62:29)

Sources:

https://www.churchofjesuschrist.org/study/general-conference/1983/04/creator-and-savior