It is of no use to stand up and preach things that may, or may not, be true. I am charged with being a dreadful dogmatist, and I am not anxious to excuse myself. When a man is not quite sure of a thing, he grows very liberal; anybody can be liberal with money which he cannot claim to be his own. The broad-school man says, “I am not sure, and I do not suppose that you are sure for, indeed, nothing is sure.” Does this sandy foundation suit you?
I prefer rock. The things which I have spoken to you, from my youth up, have been such as I have tried and proved and, to me, they wear an absolute certainty, confirmed by my personal experience. I have tried these things; they have saved me, and I cannot doubt them. I am a lost man if the gospel I have preached to you be not true; and I am content to abide the issue of the day of judgement. I do not preach doubtingly, for I do not live doubtingly. I know what I have told you to be true; why should I speak as if I were not sure?
If you want to make your own testimony tell in such a day as this, you must have something to say that you are sure about. And, until you are sure about it, I would advise you to hold your tongue. We do not require any more questionings; the market is overstocked. We need no more doubt – honest or dishonest. The air is black with these horrible blacks.
Charles Haddon Spurgeon (1834-1892), in a sermon on 1 John 5:13 entitled “The Blessing of Full Assurance,” preached on Sunday morning, May 13, 1888, not long before his 54th birthday.