NKJ Genesis 4:2b-7 “Now Abel was a keeper of sheep, but Cain was a tiller of the ground. 3 And in the process of time it came to pass that Cain brought an offering of the fruit of the ground to the LORD. 4 Abel also brought of the firstborn of his flock and of their fat. And the LORD respected Abel and his offering, 5 but He did not respect Cain and his offering. And Cain was very angry, and his countenance fell. 6 So the LORD said to Cain, 'Why are you angry? And why has your countenance fallen? 7 If you do well, will you not be accepted? And if you do not do well, sin lies at the door. And its desire is for you, but you should rule over it.'”The Net Bible notes are correct in describing the meaning of the phrase that describes Cain's “countenance” [literally face] as having “fallen”:
16 tn Heb "And his face fell." The idiom means that the inner anger is reflected in Cain's facial expression. The fallen or downcast face expresses anger, dejection, or depression. Conversely, in Numbers 6 the high priestly blessing speaks of the LORD lifting up his face and giving peace. (e-Sword)
So the text indicates clearly that Cain was depressed and that his depression was connected to his anger, anger which the context leads us to believe was toward both God and Abel. He was clearly angry because God had not accepted his offering, which means that he was angry at God. But he was also clearly angry at Abel for having been accepted by God when he had not been, which is obvious from the fact that he murdered Abel (vss. 8-9).
So what can we learn from this example? I would suggest at least three lessons:
1) Depression can result from an unrepentant heart, such as when Cain refused to heed God's counsel and repent of his sinful heart. Cain wanted God to accept him, but only on his own terms. His prideful heart would not allow him to humble himself before the Lord. Instead of confessing his sin and seeking God's grace and forgiveness, he let his anger rule him until it led to murder.
2) Depression can result from unresolved anger. Cain became depressed because he was angry and refused to deal with his anger in the right way.
The cure for the depression Cain experienced is obvious from the causes, isn't it? All Cain had to do was confess his sin and ask for God's grace. But he refused to do so.
3) Depression can result from feelings of inadequacy and perhaps jealousy of someone else. In this case Cain felt he couldn't please God and was jealous of Abel's relationship with Him. But he could not see that the problem was not really his inadequacy; it was really his refusal to come to God on God's terms.
We can also learn from Cain's example that sometimes depression is a signal of pride and unresolved sin in a person's life. Sadly, most people today resent even the suggestion of this possibility when they seek help with depression. Yet, isn't this the very issue God Himself raised with Cain in response to his depression? Indeed it is, and it is the very issue many who struggle with depression need to confront in themselves as well. In fact, although I risk sounding insensitive to many, and even cruel to some, when I say this, nevertheless I must say that in my experience some of the most depressed people I have known are also some of the most prideful or angry people I have known. I include my own past struggles with depression in this assessment.
Now, I would of course never say that this is the only – or even the primary – reason for depression for many who struggle with it, but I do believe it is a far more common source of depression than many want to admit. And the reason they don't want to admit it is the very same reason that Cain didn't want to admit it, because they would rather blame God or some other person for their dilemma than take responsibility for themselves. This tendency toward refusal to take personal responsibility for one's actions or the state of one's own heart is a growing problem in our culture, and it has made significant inroads into the churches as well.
In addition, even where unresolved sin such as pride and anger are not readily identifiable as the source of one's struggle with depression, these sins are often present as a response to depression. I have dealt with many a person who responded to their struggle with depression by becoming angry at God, for example, and who have pridefully refused to let go of their anger, and it has only made their battle with depression even more difficult.
Therefore it is all the more important that we do not shirk from raising the issue of sin when dealing with depressed people. Although we may not know their hearts the way God knew Cain's heart, we do know that they were born sinners just as Cain was, and thus we also know that sin will likely be a crucial factor in their struggle with depression, whether as its source or as a complicating factor.