1 John 4:20-21
20If anyone says, I love God, and hates a brother or sister, he is a liar, because the person who doesn't love a brother or sister who can be seen can't love God, who can't be seen. 21This commandment we have from him: Those who claim to love God ought to love their brother and sister also.
John doesn't beat around the bush very much, does he? If you say you love God but you're harboring hate toward another person, you're lying about loving God.
And, if you think today's reading is pretty direct, flip back a chapter and read 1 John 3:10: "This is how God's children and the devil's children are apparent: everyone who doesn't practice righteousness is not from God, including the person who doesn't love a brother or sister."
Jesus tells us in Matthew 25:31-46 that as we interact with others, we should act as though we were interacting with Jesus himself. With that in mind, how many times would we be short with or rude to Jesus? How often would we let him suffer alone or ignore him completely?
It's very clear that God considers it a direct correlation between how we treat those around us and whether or not we love God. That's something for us to remember as we interact with the many people in our lives.
If today's devotion spoke to you in a particular way and you feel led to share your thoughts with others, please do so.