If you want to enjoy a real spiritual feast, take a concordance to the Bible and look up the word “grace.” First notice how often this word is found in the four Gospels: only four times and only once in a doctrinal sense. Then notice how often it is used in Paul’s epistles (less than half the size of the four Gospels). Here it is found well over one hundred times and practically always in a doctrinal sense, about the love and mercy of God toward sinners and toward His own. Think of it: only once is grace referred to doctrinally in the four Gospels, yet in Paul’s epistles, less than half as large in volume, it is used more than one hundred times.
This is because St. Paul was God’s chosen apostle to make known His grace to sinners. In Acts 20:24 he speaks of “the ministry which I have received of the Lord Jesus, to testify the gospel of the grace of God.”
But on what basis could God, through Paul, proclaim salvation by free grace to sinners? Ah, now take your Bible and begin looking up those passages which refer to the cross, the death and the blood of Christ, again noticing that while Paul does not actually relate the story of Christ’s death, he has more, far more, to say about that death, and what it accomplished, than any other Bible writer. It would thrill the heart of any sincere Christian to go through the Epistles of Paul and see how much good news Paul proclaims on the basis of the death of Christ. This is why his message is called “the preaching of the cross” — God’s good news about what Calvary has accomplished for us (1 Cor. 1:17-23).
In Paul’s epistles we learn that through Christ’s death for us at Calvary believers are “justified,” “accepted” by God, and pronounced “complete in Christ.” By His death they are reconciled to God in one body, given a position at God’s right hand in the highest heavens and assured “the exceeding riches of His grace” in “the ages to come” — this and more! Riches of grace flowing from Calvary; this is the very essence of the glorious message which Paul was raised up to proclaim. Read his epistles and see. source