"Repent ye, and believe the gospel."—Mark 1:15
While the gospel is a command, it is a two-fold command explaining itself. "Repent ye, and believe the gospel."
I know some very excellent brethren—would God there were more like them in zeal and love—who, in their zeal to preach up simple faith in Christ have felt a little difficulty about the matter of repentance; and I have known some of them who have tried to get over the difficulty by softening down the apparent hardness of the word repentance, by expounding it according to its more usual Greek equivalent, a word which occurs in the original of my text, and signifies "to change one's mind." Apparently they interpret repentance to be a somewhat slighter thing than we usually conceive it to be, a mere change of mind, in fact. Now, allow me to suggest to those dear brethren, that the Holy Ghost never preaches repentance as a trifle; and the change of mind or understanding of which the gospel speaks is a very deep and solemn work, and must not on any account be depreciated. Moreover, there is another word which is also used in the original Greek for repentance, not so often I admit, but still is used, which signifies "an after-care," a word which has in it something more of sorrow and anxiety, than that which signifies changing one's mind. There must be sorrow for sin and hatred of it in true repentance, or else I have read my Bible to little purpose. In very truth, I think there is no necessity for any other definition than that of the children's hymn--
"Repentance is to leave
The sins we loved before,
And show that we in earnest grieve,
By doing so no more."
To repent does mean a change of mind; but then it is a thorough change of the understanding and all that is in the mind, so that it includes an illumination, an illumination of the Holy Spirit; and I think it includes a discovery of iniquity and a hatred of it, without which there can hardly be a genuine repentance. We must not, I think, undervalue repentance. It is a blessed grace of God the Holy Spirit, and it is absolutely necessary unto salvation.
Read more: http://www.spurgeon.org/sermons/0460.php
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