"Amazing Grace" is a Christian hymn published in 1779 with words written in 1772 by English Anglican clergyman and poet John Newton (1725–1807). It is an immensely popular hymn, particularly in the United States, where it is used for both religious and secular purposes.

Newton wrote the words from personal experience; he grew up without any particular religious conviction, but his life's path was formed by a variety of twists and coincidences that were often put into motion by others' reactions to what they took as his recalcitrant insubordination. He was pressed into service with the Royal Navy, and after leaving the service, he became involved in the Atlantic slave trade. In 1748, a violent storm battered his vessel off the coast of County Donegal, Ireland, so severely that he called out to God for mercy. While this moment marked his spiritual conversion, he continued slave trading until 1754 or 1755, when he ended his seafaring altogether. Newton began studying Christian theology and later became an abolitionist.

Amazing grace! (how sweet the sound)

That sav'd a wretch like me!

I once was lost, but now am found,

Was blind, but now I see.

'Twas grace that taught my heart to fear,

And grace my fears reliev'd;

How precious did that grace appear

The hour I first believ'd!

Thro' many dangers, toils, and snares,

I have already come;

'Tis grace hath brought me safe thus far,

And grace will lead me home.

The Lord has promis'd good to me,

His word my hope secures;

He will my shield and portion be

As long as life endures.

Yes, when this flesh and heart shall fail,

And mortal life shall cease;

I shall possess, within the veil,

A life of joy and peace.

The earth shall soon dissolve like snow,

The sun forbear to shine;

But God, who call'd me here below,

Will be forever mine.

John Newton, Olney Hymns, 1779

Source: Wikipedia (https://en.wikipedia.org/wiki/Amazing_Grace)