Charles Wesley (1707‑1788) wrote a poem that forms the basis of this hymn. It was in seven stanzas of four lines with no chorus or refrain. It was first published in 1739 in Hymns and Sacred Poems.

It was amended by George Whitefield in 1758. Whitefield was a preacher in the mould of those that were called "Methodists." Further changes occurred over the years to some degree. During the period when it was written preachers and hymn leaders apparently, according to Andrew Gant, would alter hymns when they wanted to emphasise certain thoughts or points. Although it is reported that the Wesleys did not like people altering their hymns. Vaughan Williams tried to restore a word back to Wesley’s original words but congregations just laughed so the change was farcical.

The tune has a similar story. The basis for the tune that is known so well in the 21st century comes from German Jewish composer Mendelssohn who composed it in 1840. He was a superstar in that day according to Gant. The tune first published in 1856 was written by William Hayman Cummings who matched this tune to a version of Wesley’s poem. This tune is known as Mendelssohn.

Wherever the words are sung, at home, in a church building, outside or in a concert hall–no carol service would be complete without it.

Here are some Bible verses which are thought to have inspired the writer:

Matthew 2:1‑2 When Jesus was born in Bethlehem...there came wise men from the east...saying, Where is he that is born King of the Jews? for we have seen his star in the east, and are come to worship him.

Romans 5:8‑11 (RSV) God shows his love for us in that while we were yet sinners Christ died for us. Since, therefore, we are now justified by his blood, much more shall we be saved by him...for...while we were enemies we were reconciled to God by the death of his Son.

Psalm 67:4 O let the nations be glad and sing for joy: for thou shalt judge the people righteously, and govern the nations upon earth. Selah.

Micah 5:2 Bethlehem Ephratah...out of thee shall he come forth unto me that is to be ruler in Israel; whose goings forth have been from of old, from everlasting.

Isaiah 7:14 The Lord himself shall give you a sign; Behold, a virgin shall conceive, and bear a son, and shall call his name Immanuel.

Luke 2:9‑14 The angel of the Lord came upon them, and the glory of the Lord shone round about them: and...the angel said unto them, Fear not: for, behold, I bring you good tidings of great joy, which shall be to all people. For unto you is born this day in the city of David a Saviour, which is Christ the Lord...And suddenly there was with the angel a multitude of the heavenly host praising God, and saying, Glory to God in the highest, and on earth peace, good will toward men.

Isaiah 9:6‑7 For unto us a child is born, unto us a son is given…The Prince of Peace. Of the increase of his government and peace there shall be no end, upon the throne of David, and upon his kingdom.

Malachi 4:1‑2 For, behold, the day cometh, that...shall the Sun of righteousness arise with healing in his wings; and ye shall go forth.

Luke 1:77‑79 To give knowledge of salvation unto his people by the remission of their sins, through the tender mercy of our God; whereby the dayspring from on high hath visited us, to give light to them that sit in darkness and in the shadow of death.

John 8:12 Spake Jesus...I am the light of the world: he that followeth me shall not walk in darkness, but shall have the light of life.

John 11:25 Jesus said unto her, I am the resurrection, and the life.

Revelation 15:4 Who shall not fear thee, O Lord, and glorify thy name? for thou only art holy: for all nations shall come and worship before thee.

1 Corinthians 15:22 For as in Adam all die, even so in Christ shall all be made alive.