There are three conditions in which the water in that engine may be. First, the boiler may be full and the water clean and clear; or, secondly, the boiler may not only be full but the water may be hot, very hot, hot enough to scald you, almost boiling; thirdly, it may be just one degree hotter and at the boiling point, giving forth its vapor in clouds of steam, pressing through the valves and driving the mighty piston which turns the wheels and propels the train of cars across the country.
So there are three kinds of Christians. The first we will call cold water Christians, or, perhaps better, clean water Christians.
Secondly, there are hot water Christians. They are almost at the boiling point.
One degree more, we come to the third class of Christians, the boiling water Christians. The difference is a very slight one; it simply takes one reservation out, drops one "if," eliminates a single touch, and yet it is all the difference in the world. That one degree changes that engine into a motive power, not now a thing to be looked at, but a thing to go.