I'm not religious, but the seven deadly sins are a great list of things to be aware of. Staying clear from them can help improve your life in more ways than one. One of those ways is in your romantic life. Here are the seven deadly relationship sins you should never commit:
1) Obsessive Lust
Stemming from an initial lustful desire for the other person. But, due to increased insecurity and low self-esteem, fear of rejection and being alone, lust can lead to one person becoming obsessed with the other. It can lead to snooping on their social media accounts. Lack of trust builds up and eventually resentment takes over on both sides. Basically, they want to be the only one in their partner's life. It's not healthy, nor is it good.
Again stemming from insecurity and lack of trust. Jealousy can creep in on a relationship and cause problems. It could be that one person is envious of their partner's achievements or happiness, or it could be that someone else is paying their girl/boyfriend a bit too much special attention and that's both angering and hurting them, so they lash out. Or it could be a friend of their partner's who's doing really well and their success threatens them, so they try to discredit their success, and look painfully pitiful in the process.
Being too lazy to ever do anything. Never wanting to go out and try new things. All they want to do is stay in and eat pizza and watch Netflix. They barely even have the energy to have sex with you. What's the point in dating someone who doesn't even have the energy to leave their house once a month? There is no point as far as I can see.
Having anger issues is a big deal and needs to be seen to. If your other half can't handle it when things don't go their way and lash out with tantrums, throwing things, breaking stuff, even hitting you, then you need to ditch them. You don't have to put up with that crap. They need to check themselves because they've already wrecking themselves.
Not looking after themselves, but expecting you to look your very best at all times. Not solely in relation to their (poor) diets, over-consuming their time with everything and everyone other than you. But also in the way they always expect you to be there, even though they never make time for you.
Wanting everything to be about them, wanting all of your attention and not giving any back. Never, ever caring about your needs or your desires. Being greedy and selfish in the bedroom, as well as out. Who would be with someone like that when they could be with someone who actually appreciates them?
Being too proud and self-centered to ever be truly grateful to have someone who cares for them in their life. Thinking that they're the best and that everyone else should be thanking them for choosing to be around. Maybe even so cocky that they openly flirt with other people in front of their partners. Maybe they cheat regularly, they don't think there would be any consequences, who would break up with them, after all? Shut that down, they just aren't worth it.