The following is from a message by Thomas Watson entitled, A Divine Cordial from 1663:
"Grace changes the heart!
Therefore if any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new. - 2 Corin. 5:17
The true Christian has a great change wrought. Not a change of the faculties—but of the tendencies. He is altered from what he was before. His body is the same—but not his mind. Oh what a metamorphosis does grace make!
There is a change wrought in the UNDERSTANDING. Before, there was ignorance—but now there is light. The first work of God in the creation of the world was light—likewise it is in the new creation. He now says, 'I once was blind—but now I see!' (John 9:25). He sees such evil in sin, and excellency in the ways of God—as he never saw before! It is a marvelous light, because it is more penetrating. Other light may shine upon the face—but this light shines into the heart, and enlightens the conscience (2 Cor. 4:6).
There is a change wrought in the WILL. The will, which before opposed Christ—now embraces Him. The will, which was an iron sinew against Christ—is now like melting wax, and readily receives the stamp and impression of the Holy Spirit. The will now moves heavenward—and carries all the affections along with it. The will now says, 'Lord, what wilt thou have me to do?' (Acts 9:6). Before, the will kept Christ out; now, it keeps sin out! Oh what a happy change is wrought here!
There is a change wrought in the CONDUCT. He who is saved, walks directly contrary to what he did before. He once walked in envy and malice—now he walks in love! He once walked in pride—now he walks in humility. In the heart there is a new birth—and in the life there is a new conduct.
Thus we see what a mighty change grace makes.
How far are they from salvation, who never had any change!They are the same today—as they were forty or fifty years ago.They are as proud and carnal as ever! They have had no change in their heart. Let not them think to leap out of the harlot's lap (the world) into Abraham's bosom! They must either have a gracious change while they live—or a cursed change when they die!"