What was one of Paul's favorite words in his letters?

Grace was one of Paul's favorite words. In his letters he continually refers to the grace of God, as shown in the greeting “Grace be unto you” and in his thanksgiving for the grace of God given to believers by Jesus Christ. This theme appears repeatedly.

The speaker explains that “Grace be unto you” must have been one of Paul’s favorite words because he is always referring to the grace of God. In verse 4 Paul thanks God always on the Corinthians’ behalf for the grace of God given them by Jesus Christ. The context stresses that very few church people or professing Christians comprehend the grace of God. Many assume God is still demanding, a rough lawgiver who punishes failure to keep His commands and laws. But that is not grace. The vilest sinner is still the object of God’s love and attention because of His grace.

1 Corinthians 1:3

Grace be unto you, and peace, from God our Father, and from the Lord Jesus Christ.

Why does Paul talk about grace so often in his letters?

Paul frequently speaks of grace because it was one of his favorite words and he continually referred to the grace of God. Grace reveals that God is not merely a demanding lawgiver; even the vilest sinner remains the object of God's love and attention because of His grace.