Loving God, Hating Your Brother?

1Jo 4:20 If anyone says, I love God, and hates his brother, he is a liar. For if he does not love his brother whom he has seen, how can he love God whom he has not seen?


This is an argument i just don't get. It's a lot easier to "love" someone you DON'T see! They can never do anything to annoy, upset, or aggravate you. It's true that neither can they do anything to endear themselves to you if you have no real relationship but whatever the last thing that happened between you is, that's what you remember. Maybe it's because that's not really considered love.
Besides, saying one doesn't 'see' God - no, i don't see 'Him' walking around, don't 'see' Him hugging me or helping me understand something. But He does have a tangible presence; otherwise He's just a concept. Been there, done that. Once He's shown Himself to you, it's way more and you really can't say you've never seen Him. The word 'see' carries a different connotation from then on and physically laying eyes on Him isn't the point anymore.