As per lot of accounts and with verses from his epistles like the ones quoted below, Paul (AD 5 – 67) seems to be the numero uno as far as grace preachers are concerned…
“the law entered, that the offence [sin] might abound, but where sin abounded, grace did much more abound” (Romans 5:20).
“even so might grace reign through righteousness unto age-lasting [aionian] life by Jesus Christ our Lord” (Romans 5:21).
For sin shall no longer be your master, because you are not under the law, but under grace. — Romans 6:14 (NIV).
“And if by grace, then it is no more of works: otherwise grace is no more grace. But if it be of works, then it is no more grace: otherwise work is no more work.” Romans 11:6
I do not set aside God’s grace, because if righteousness could come through the law, then Christ died for nothing! Galatians 2:21
“For by grace are you saved through faith; and that not of yourselves; it is the gift of God: not of works lest any man should boast.” Ephesians 2:8
Below is a small insight on same point of view:
To the unbiased believer of the Word of God, there is overwhelming proof that the secret of God’s eternal purpose and of His good news to man was first communicated by revelation to the Apostle Paul, that he in turn might make it known to others. Not only does Paul himself declare this by divine inspiration but his declarations are amply confirmed by a comparison of his message and ministry with the messages and ministries of all his predecessors.
But while particular distinctions have often been noted in this connection, we feel that too little attention has been given to the broader aspects of his message and ministry as compared with those of his predecessors. Those great, grand truths which he was commissioned to unfold were the constant subject of his discourse and his letters, and his life and conduct harmonized perfectly with those truths and with the dispensation he ushered in.
THE DISPENSATION OF GRACE
Let us begin with his proclamation of grace.
We are sometimes asked: “Did not others before Paul speak of grace?”
Yes, others before Paul did speak of grace, but before we assume too much from this, let us consider a few basic facts:
It is not merely Paul, but the inspired Word which declares that “the dispensation of the grace of God” was committed to him (Eph. 3:2) and that it was his “ministry… received of the Lord Jesus” to make known “the gospel of the grace of God” (Acts 20:24). this claim was made for none of his predecessors, nor did any of them even mention the dispensation or the gospel of the grace of God so far as the record is concerned.
To the believer this evidence should be conclusive that Paul was God’s chosen vessel, raised up especially to proclaim the message and program of grace. But to those who hesitate to accept these inspired statements at their face value, we have further important evidence to offer in the fact that no other bible writer—not even all the others put together—have so much to say about grace.
The Hebrew equivalent of Paul’s word for grace is found only 68 times in the whole Old Testament (which is nearly twelve times the size of Paul’s epistles including Hebrews) and then not always relating to God’s grace, and never to the dispensation of Grace.
In the four Gospels (nearly twice the size of Paul’s epistles) the word grace (Gr. charis) with its derivatives appears in the original only 13 times (much less often in the English A.V.) and then rarely in even a doctrinal, much less a dispensational, connection.
By comparison, the epistles of Paul, only about one twelfth the size of the Old Testament and one-half the size of the four Gospels, employs the word grace and its derivatives no less than 144 times, more often than all the rest of the Bible together and nearly twice as often as the whole Old Testament and the four Gospels together! And then, in Paul’s epistles the word grace is nearly always used doctrinally, in connection with the dispensation of Grace.
Every epistle signed by his name opens with a proclamation of grace and peace “from God our Father, and from the Lord Jesus Christ.” In the epistles we find that we are “justified freely by [God’s] grace” (Rom. 3:24), that “where sin abounded grace did much more abound” (Rom. 5:20) that grace might reign (5:21). There we read that we are “not under the law, but under grace” (6:14), that “God is able to make all grace abound” toward us that we may “abound to every good work” (II Cor. 9:8), that it is God’s purpose for “the ages to come” to “show the exceeding riches of His grace in His kindness toward us through Christ Jesus” (Eph. 2:7). And we could go on and on adding up the evidence that “the dispensation of the grace of God“ was indeed committed especially to Paul to make known to us.
An examination of the book of Acts reveals a similar comparison. There the word grace in the original is found four times before the raising up of Paul and 12 times after. Before the raising up of Paul it is not used once of the dispensation of Grace or of salvation by grace, but in later Acts, after his conversion, not only is the word used more often, but immediately it appears in connection with the dispensation of Grace.
When Barnabas “had seen the grace of God” in saving Gentiles at Syrian Antioch, he “was glad” (Acts 11:23). When Jews and religious proselytes at Pisidian Antioch received Paul’s proclamation of salvation through Christ, without the law, he and Barnabas “persuaded them to continue in the grace of God” (13:38,39,43). At Iconium, Paul and Barnabas gave bold testimony to “the word of His grace” (14:3). Later Peter confirmed Paul’s message, publicly declaring his conviction: “We believe that through the grace of the Lord Jesus Christ we [Jews] shall be saved even as they [Gentiles]” (15:11). At Ephesus, Apollos proved helpful to “them…which had believed through grace” (18:27). On his way to Jerusalem Paul declared his determination to fulfill his Christ-given commission “to testify the gospel of the grace of God” (20:24) and then commended the Ephesian elders to “the word of [God’s] grace” (20:32).
The above compilation is partially quoted from: LINK