Subjects suitable to an immortal being

A reminder from Spurgeon to deal in our ministry with subjects suitable to an immortal being, taken from a sermon on The Word of the Cross (#1611):
If I were able to explain to a general audience how to make unlimited profit upon the Stock Exchange, or in some other market, all the world would listen with profound attention; and if I put my point clearly I should be pronounced a really clever preacher, a man well worth hearing; but when the sermon is only about the word of God, and eternity, and the soul, and the blood of Jesus - most people turn on their heel; they are not sure that they have souls, and they refuse to argue upon the supposition of a future existence, which is an old wife's fable to them. As for eternity their philosophy has no room for it, and they do not concern themselves about it. One said in argument the other day, "I believe I shall die like a dog." I could give him no better reply on the spur of the moment than to say, "If I had known that you were a dog I would have brought you a bone." As I had the notion that he would live for ever I came to talk to him upon subjects suitable to an immortal being, but as I found out that he was going to die like a dog, what could I do for him but provide such cheer as the creature could enjoy? These men call the gospel foolishness because they look after the main chance, and care more for the body than for the soul. One of their wise men said, "Why do you preach so much about the world to come, why not preach about the world which now is? Teach these people how to ventilate their sewers, that is a much more needful matter than their believing on Jesus." Well, sanitary matters are important, and if any of you feel that you have nothing to live for but ventilating sewers I wish you would live at a great rate, and get it done as quickly as you can. Meanwhile, as we are convinced of the need of other things besides drainage, and as many of us expect soon to take our happy flight to a place where there are no sewers to ventilate, we shall look into those things which concern our future life, seeing they also fit us for the life which now is.