Sometimes we don't understand the Bible because we read it through the lens of our culture. I had that experience with 1 John 4:20
"Whoever claims to love God yet hates a brother or sister is a liar. For whoever does not love their brother and sister, whom they have seen, cannot love God, whom they have not seen."
It's a verse that has always bothered me. I've got the general gist. If I say I love God, but don't love people, I'm deceived. Wrong. What I have struggled with is the seeing part. Because when I read the second line of the the verse I think to myself, "The reason I don't love people is that I can see them! I know them. They wind me up. Get on my nerves. Let me down. Don't live up to my expectations. In fact I think that it would be a lot easier to love people if I saw them less. Absence makes the heart grow fonder. Because with absence comes a rose tinted view of what they're like!"
I wonder if you have spotted my assumption? It is rooted in the way that our culture defines love. Love is the way someone else makes me feel. To fall in love is for someone to make me feel excited and aroused about being with them. With clothes on, but preferably without. To love my family is to feel a warm cosy security when I am with them. It is when my heart wells up with joy towards my children. Love is primarily something that I receive from others that then makes me feel a particular way. It's all about me!
So if you don't feel "good" about someone else. If they make you feel irritated or angry or maybe simply just emotionally numb. Then you no longer love them. It's time to change your husband/wife/partner/friend for someone else.
But that's not what the Bible means by love. In fact John defines love just a few verses before hand:
"This is love: not that we loved God, but that he loved us and sent his Son as an atoning sacrifice for our sins." (1 John 4:10).
God's love is that he chooses to send his Son to die in the place of people who don't love him. In fact the Bible describes us as people who hate him. Who want him out of our lives so we can do what we want.
That means that to love someone is to put their good above your own. However, they make you feel. Often at great cost to yourself.
Suddenly 1 John 4:20 makes sense! Because it's hard to know how to love a God who you can't see. Who needs nothing from me. Who is perfectly content within Himself. But it's much easier to love someone you can see. Who has visible tangible needs. Who is designed to experience love from other people.
I wonder if when we say, "I love God!" a lot of the time we're speaking from the world's perspective. What we're really saying is, "I love the way that God makes me feel!" Whereas when God says, "I love you." He is saying I am committed to you despite the way you treat me, to the extent that I will die in your place, suffering your punishment.