We may behave badly for attention. Then when we think it gets too normalised or accepted we get worse. That is life but religion says we will never be content with the evil we do.
With religion, evil or sin, is seen as a rejection of God’s just and loving authority over the universe and human life. So even a 'small' evil then is a very big thing in terms of the message it sends to God. If God is good for the universe and all in it then that sends a message to everybody else too. And to yourself. The self-abusing element is interesting. If you want to be harmed you will not be satisfied for harming yourself gives rise to wanting a new way to do it or to do more of it.
Religion says sin starts with the heart with an evil intention. We want harm to come to others. So the evil of having the intention will be frustrating until you do something with it. We can be sure we all have vindictive or harmful wishes.
Privatised evil is a universal problem and we all have it to one degree or another. The person sees it as being about what harm and horror it does to him or her as if that is all that matters. In this view, the only evil you reject is the one that attacks you. The immoral nature of evil does not matter. All you lament is how it came to you. Many people that claim to be about fighting evil in their community are only worried about the part of it that endangers them. For all we know, moral crusaders may be only motivated around privatised evil.
The Bible says you are not forgiven for just what evil you do but for what you are. You have to ask pardon for who you are. The actions are secondary for they only appear for you are bad as a person in the first place. The Bible rejects the notion that evil doing is only a matter of choice, and it says it is down to our fallen evil nature. If this doctrine is true then fair enough. But if it is not, or if nobody has reason to believe it even if it is true, then it could be a way of identifying with evil. You want evil to be you and you it. It gives you an excuse too for hating the sinner with the sin.
Adam and Eve wanted the tree of good and evil as if they could look at and understand evil without being captured or polluted by it. The Church says that was their mistake. They were indeed captured and ruined. Their experiment put evil in them. They didn’t even need to go and steal or murder. It got in there and then. If evil is that adept and effective and clever with beings made good and innocent, imagine what it would be like with beings like us who are not! We all experiment with evil. We do it over and over again as if we are finally going to get a good and ideal result the next time.
Religion says that evil acts like it is dissatisfied with itself. Those who embrace it feel less than satisfied too. They just feel it. So it’s a double problem. And don’t forget that as evil will have the emotional consequences of fear and insecurity and disdain from others that adds to the unhappiness.
We are told that as evil is misdirecting so it stands to reason that you are detached from reality a bit so your struggles against the good and struggles with evil will lead to rage and that will be taken out on innocent persons.
All those dissatisfactions flow from how evil feels threatened for it is a lie and thrives on lies and so it is insecure for it is not final and unchangeable like truth is. Truth is not anybody's friend but they need to embrace it for it cannot be wished away. The alternative is worse. To be evil you have to be prepared to lie. And lies lead to more lies which is very unsatisfying and yet you will still look for satisfaction.
Aristotle and St Thomas Aquinas and indeed Christianity say that the evil person does evil for he thinks there is good to come from it. So is evil just a mistake then? It says the person by trying to do evil to get good is aiming at an unreal or the wrong good. Eg you kill yourself to end mental suffering when in fact trying to live with it for another day would be the right thing to do. They say the evil person hopes for good and foresees evils that may happen and goes ahead with what could bring the foreseeable evils about.
This is a rationalisation. If you want good health that is a good goal and does not become a bad one simply by using the wrong means to get it. Religion does admit that evil involves a mistake which is why it is so unsatisfying. But it denies that it is only a mistake. We see here that teaching is incoherent. A mistake however destructive is not intentionally malicious or selfish.
If evil is a lack of good and the wrong way to get a good then it stands to reason it is going to be inherently unsatisfying. It may seem good for a time but that only adds to the dissatisfaction that is coming.
We conclude that religions that have too few morals or too many, or which cannot give sensible understandable reasons for following their ethical mores, will lead to you doing unsatisfactory evil. That will increase your propensity to doing harm. In fact being involved with such religions is itself harm.