Now, with the little crab, who also lives in the same neighborhood with the oyster, it is quite different. The crab has eyes, and can see the hungry fish that comes to eat him up. He has legs, with which to try and run away; but the fish can swim so much faster than the little crab can run that he is sure to be devoured before the race is half over. So what do you think the little crab does? He crawls along quietly, and creeps into the shell with the oyster, and the oyster and the crab enter into a kind of partnership for mutual protection. After this, when the oyster opens his shells, the little crab uses his eyes very diligently to look around, and watch for the approach of any fish. As soon as he spies any sly fish coming near, he pinches the oyster, and immediately the oyster closes his shells very tightly, and the oyster and the crab are both within, safely protected from the fish. Now, boys and girls, we are something like the oyster. We are constantly exposed to the danger of being destroyed by sin. We cannot see sin, we cannot hear sin, we cannot perceive it by any of our senses. So God has given us a conscience, which means "to know with God." When you are tempted to do a sinful act, it is conscience that quickly whispers, "Now that is wicked," "If you do that, God will be displeased." Let me illustrate this thought. One real pleasant day, when the birds are singing, and everything is attractive out of doors, Johnnie thinks how hard it is to be studying his lessons in what he calls a prison of a school-room. He knows that papa and mamma will not give him permission to stay at home; so a little before nine o'clock, as he saunters towards the school, Satan suggests to him to play "hookey," and when he comes to the corner of the street, looking back to be sure that no one sees him, he turns the corner to remain out of school, intending to come home at the regular time for dinner and escape discovery. Just as soon as he turns the corner, and even before that, conscience has seen the danger, and whispers strong and clear, "Johnnie, this is wicked; you will surely get into trouble, and you will make papa and mamma sad, and also displease God." Now, if Johnnie does not turn right back when conscience warns him, he is sure to go on without having any pleasure all that forenoon, because his conscience continues to warn and reprove him. [Illustration: "Willie is more frightened than the dog."] Or suppose that Willie goes down the street and sees Mr. Brown's dog a little ways off. He looks around quickly for a stone, and immediately conscience says, "Now, Willie, don't hit the poor dog, for the stone will cause him pain, just as it would if some one were to hit you with a stone." But Willie does not listen to conscience. He throws the stone with all his might. It strikes on the pavement, just by the side of the dog, glances and breaks in many pieces the large plate glass in the window of the drug store.