I. First, then, WHAT IS PRESUMPTUOUS SIN? Now, I think here must be one of four things in a sin in order to make it presumptuous. It must either be a sin against light and knowledge, or a sin committed with deliberation, or a sin committed with a design of sinning, merely for sinning's sake, or else it must be a sin committed through hardihood, from a man's rash confidence in his own strength. We will mark these points one by one.
1. A sin that is committed willfully against manifest light and knowledge is a presumptuous. sin. A sin of ignorance is not presumptuous, unless that ignorance also be willful, in which case the ignorance itself is a presumptuous sin. But when a man sins for want of knowing better - for want of knowing the law, for want of instruction, reproof, advice, and admonition, we say that his sin, so committed, does not partake to any great extent of the nature of a presumptuous sin. But when a man knows better, and sins in the very teeth and face of his increased light and knowledge, then his sin deserves to be branded with this ignominious title of a presumptuous sin. Let me just dwell on this thought a moment. Conscience is often an inner light to men, whereby they are warned of forbidden acts as being sinful. Then if I sin against conscience, though I have no greater light than conscience affords me, still my sin is presumptuous, if I have presumed to go against that voice of God in my heart, an enlightened conscience. You, young man, were once tempted (and perhaps it was but yesterday) to commit a certain act. The very moment you were tempted, conscience said, "It is wrong, it is wrong" - it shouted murder in your heart, and told you the deed you were about to commit was abominable in the sight of the Lord. Your fellow-apprentice committed the same sin without the warning of conscience; in him it was guilt - guilt which needs to be washed away with the Saviour's blood. But it was not such guilt in him as it was in you, because your conscience checked you; your conscience told you of the danger, warned you of the punishment, and yet you dared to go astray against God, and therefore you sinned presumptuously. You have sinned very grievously in having done so. When a man shall trespass on my ground, he shall be a trespasser though he have no warning, but if straight before his face there stands a warning, and if he knowingly and willingly trespasses, then he is guilty of a presumptuous trespass, and is to be so far punished accordingly. So you, if you had not known better; if your conscience had been less enlightened, you might have committed the deed with far less of the criminality which now attaches to you, because you sinned against conscience, and consequently sinned presumptuously. ...