Grace is generally defined as undeserved favor.

Do you know that the hymn Amazing Grace made it to the top of the British pop chart in the 80s? Indeed, this hymn has been sung in church countless times. And it has been translated into different languages and it has been sung in a dozen different ways.

Amazing Grace, how sweet the sound
That saved a wretch like me;
I once was lost but now am found,
Was blind, but now, I see.

Grace is generally defined as undeserved favor. Hence, when Paul wrote about having been saved by grace, he meant precisely that. We do not deserve to be saved; and we cannot earn our salvation. We are saved because God shows his favor towards us when we least deserve it.
The writer of the hymn, John Newton (1724-1807), truly experienced the undeserved favor of God. Soon after his conversion, Newton, who was a captain of a slave-trading ship, had a growing conviction of the cruelty of his work. Later, he worked hard for the abolition of slavery. His hymn, Amazing Grace alludes to the wretchedness of his former profession, and the blindness of not seeing the inhumanity of enslaving fellow humans.
In this regard, he was very much influenced by the work of William Wilberforce, the Christian Member of Parliament whose life work was focused on the repeal of the law legalizing slave-ownership. Both John and Charles Wesley also asserted tremendous influence on his anti-slavery activities.
We too should never cease to be in awe of the grace of God in our lives. Every time I sing this hymn I marvel afresh at God’s amazing grace in my life. And the most inspiring fact of John Newton was that a slave trader became a slave to the Lord Jesus Christ.
Amazing Grace, how sweet the sound
That saved a wretch like me;
I once was lost but now am found,
Was blind, but now, I see.