Two ways to view & respond to negative feelings
Cain refused to come to God with faith – and God turned him down. Now let's see what his reaction was (read 4:5b). Even his face showed that he was angry – he took on a moping, brooding countenance. His emotional reaction 4:5a was a rage (toward God for turning him down?; toward Abel out of jealousy?) that was soon to boil over into violence.
So God initiated toward Cain and asked questions designed to counsel him (read 4:6,7). Notice that God doesn't unconditionally validate Cain's feelings. "You feel bad? That's because your attitude is wrong! Turn it around, and you'll feel better! But if you don't turn it around, things will a lot worse, so deal with it now!"Sin is not just a wrong behavioral choice; it is a power that destructively exploits our wrong attitudes. Either we master it by choosing the proper attitude, or it will master us.
God corrects the way Cain is reacting to this situation, and He counsels him to view and react a different way to his angry feelings.
Cain's way makes two mistakes. It unquestioningly validates strong negative emotions (see God's questions about Cain's and Jonah's anger), and it is deterministic ("my circumstance made me feel this way, and my feelings make me react in this way"). Left unchallenged, this view and response creates its own "feedback loop" that strengthens both of the above wrong assumptions. Does this sound familiar? Unfortunately, these assumptions are very common in our culture.
God's way acknowledges that negative circumstances can cause negative emotions. These are not necessarily wrong, and we can process/express them in healthy ways (e.g., biblical lament). But God calls on Cain/us to focus more on our attitude – by prayerfully reflecting on how it may be affecting the way we feel ("Why are you angry?"), and by prayerfully choosing a godly response going forward ("if you do well")? God promises that as we do this and choose to act in ways consistent with a godly attitude, our emotional lives will (immediately or gradually) improve ("your countenance will be lifted up"). See also Ps. 34:12-14; Jn. 13:17 for this theme.
Seen in this way, our negative emotions usually function like the TROUBLE-LIGHT on your car's dashboard. When it comes on (like it did with me not long ago), I can make two mistakes. The first is to ignore it ("It's probably just a short. I'll put tape on it so I won't see it"); the second is to view it as the main problem ("If I can unscrew it, my car will be OK"). No, the TROUBLE-LIGHT is not the root problem, but rather the warning system that is designed to alert me to a problem under the hood. I should check under the hood and see what needs to be repaired – and then the TROUBLE-LIGHT usually goes off.
In the same way, when I notice that I am angry, depressed, anxious, etc. (especially when severe and/or chronic), I need to prayerfully "take a look under the hood" for attitudes/behaviors that are contrary to God's will (read Ps. 139:23,24; e.g., hiding &/or justifying sin; nursing resentment or bitterness; self-pity; envy/jealousy; self-absorption; prideful self-reliance; idolatrous relational demands; self-recrimination). How often He answers this prayer! As I choose to admit my wrong attitude to God, and to ask Him to help me change it ("repent") – and as I by faith take action consistent with the proper attitude (EXAMPLES), my emotional state usually improves – sometimes quickly and dramatically, sometimes more slowly and subtly.
This should be our normal approach to negative emotions. It is amazing how often this leads to more emotional health! If we try this over a period of time without relief, then we should consider professional counseling and even possible medication. Because we live in a fallen world, there are cases in which this is needed – but they are the exception, not the norm. And medication doesn't solve the problem; it can help us to do the hard above work (ME WITH ANTI-DEPRESSANTS).
But Cain did not listen to God's counsel. Rather than change his attitude, he followed his negative emotions and killed his brother (read 4:8). But the story doesn't end here. The following interchange between God and Cain illustrates two contrasting biblical themes – that we can harden ourselves against God, but that God continues to pursue us.
Human hardening vs. God's pursuit
Read 4:9a. God gives Cain an opportunity to admit his sin and take responsibility for it. But Cain stiff-arms him with a lie and an evasion of responsibility (read 4:9b).
Read 4:10-12. God confronts Cain with what he did and informs him of the disciplinary consequence (loss of vocation and expulsion from his family). Cain responds by complaining that his punishment is too great (read 4:13) – when in fact it is amazingly lenient), and by assuming God doesn't care about him (when God is reaching out to him in mercy).
Read 4:14. Cain complains that Adam's descendants will eventually kill him because of what he did to Abel – but God mercifully promises to protect his life (read 4:15). After all this, Cain complains that God is driving him from His presence – yet it is Cain who chooses to leave the presence of the Lord (read 4:16).
This is another major theme in the Bible – humans' rejection of God and His will, but God's gracious patience as He continues to reach out to us with an invitation to repent.
You can harden yourself against God – and the more you harden yourself, the more difficult it becomes to turn to Him. This is the most terrible consequence of the misuse use of your free choice (read Heb. 3:7,8,12).
But you cannot stop God from pursuing you (read Hos. 2:5-7). As long as you are alive in this world, God will keep reaching out to you as He did with Cain.
The only unforgivable sin is to refusing to receive God's forgiveness. Yes, our sins deserve God's judgment – the ground called out to God for justice concerning Abel's blood (4:10). But Jesus' blood speaks better than Abel's (Heb. 12:24) – it speaks "Mercy" because it provides the basis for God's forgiveness. Have you taken your place as a Cain with regard to your ungodly attitudes and behaviors? Have you acknowledged God's patience with you? Have you taken your place under Christ's blood and received God's mercy?