Let us learn therefore by this history to know a Cain, and to guard best against him when he speaks the most friendly, and as a brother to a brother. For it is in this way that our adversaries, the bishops and the Pope, talk with us in our day, while they pretend a desire for concord and peace, and seek reconciliation of doctrines; whereas if an opportunity of seizing us and executing their rage upon us should present itself, you would soon hear them speak in a very different tone. For all the time there is death in the pot, 2 Kings 4:40; and under the best and sweetest words there lies concealed a deadly poison.
V. 8b. And it came to pass, when they were in the field, that Cain rose up against Abel his brother, and slew him.
Here then you see the deceptiveness under the above dissembled conversation of Cain with his brother. Cain had been admonished by his father with divine authority to guard against sin in the future and to expect pardon for the past through the promised Seed. But Cain despises both admonitions and indulges in his sin, as all the wicked do. For true is the saying of Solomon, "When the wicked cometh, there cometh also contempt, and with ignominy cometh reproach," Prov. 18:3.
Just in the same manner our ministry of the Word at the present day deserves no blame. We teach, we exhort, we rebuke, we turn ourselves every way, that we may recall the multitude from the security of sin to the fear of God. But the world, like an untamed beast, still goes on and follows not the Word, but its own lusts, which it strives to palliate under the appearance of what is honest and right. The prophets and the apostles also stand before us as examples of the same labor in vain, and we also are taught the same by our own experience. Our adversaries being so often admonished and convicted know they are doing wrong, and yet they lay not aside their murderous hatred against us.
From the case of Cain therefore learn what a hypocrite is; namely, one who pretends to the worship of God and charity, and yet at the very same time destroys the worship of God and slaughters his brother. And all this semblance of good-will is only intended to create the better opportunities of doing the harm designed. For if Abel had foreseen the implacable wrath and the truly diabolical fury of his brother, he might have saved his life by flight. But as Cain betrayed nothing of this kind while he talked with his brother in seeming affection and put on the appearance of his usual good-will, Abel perished before he felt the fear of danger.
There is no doubt that Abel, when he saw his brother rising up against him, entreated and implored him not to pollute himself with this awful sin. But a mind thus beset by sin pays no regard to prayers, nor heeds uplifted hands. Just as Cain therefore had despised the admonition of his father; so now also he equally despises his brother, fallen on his knees before him.
These things instruct us in that cruel tyranny of Satan, under which our nature when involved in sins is bound. Hence Paul calls such, "The children of wrath," Eph. 2:3; and declares that such are "taken captive by Satan at his will," 2 Tim. 2:26. For when we are mere men; that is, when we apprehend not the blessed Seed by faith, we are all like Cain, and nothing is wanting but an opportunity to murder our brother. For nature, destitute of the Holy Spirit, is driven by that same evil spirit by which Cain was driven to murder. Whereas if there were in any one those sufficient powers or that free-will of which men talk, by which a man might defend himself against the assaults of Satan, these gifts of nature would most assuredly have existed in Cain, to whom belonged the first birth-right and the promise of the blessed Seed. But it was not so. And the condition of all men is the same. Unless nature be helped by the Spirit of God, it cannot uphold itself nor stand. Then why do we vainly and absurdly boast of free-will? Now follows another remarkable passage.
II. V. 9. And Jehovah said unto Cain, Where is Abel thy brother? And he said, I know not: Am I my brother's keeper?
Good God! into what depth of sin does our miserable nature fall, when driven onward by the devil. At last murder was committed on a brother. And perhaps murdered Abel lay for days unburied. When therefore Cain returned to his parents at the accustomed time, and Abel returned not with him, the anxious parents said to him, Cain, thou art here, but where is Abel? Thou art returned home, but Abel is not returned. The flock is without their shepherd. Tell us therefore where thy brother is? Upon this, Cain, growing indignant, makes answer to his parents, by no means with due reverence, "I know not: Am I my brother's keeper?"
But it happened to Cain as to all the wicked, that by excusing he accused himself. Agreeably also to the words of Christ our Lord, "From thine own mouth will I judge thee, thou wicked servant," Math. 18:32. The heathen had also a striking proverb among them, "A liar ought to have a good memory." Such was the judgment of heathen men, though they knew nothing of the judgment of God and of conscience, and were capable of judgment and giving admonition concerning natural and civil things only. And true it is that liars expose themselves to many dangers of detection, and betray many facts, by which they may be convicted and refuted. Hence the Germans have this proverb, "A lie is a very fruitful thing." For one lie begets seven other lies, which become necessary to establish the first lie, and to make it wear the face of truth. And yet it is impossible after all to prevent conscience from betraying itself at times, if not in words then in countenance and gesture. This will be proved by numberless examples hereafter. I will cite one example here.