Two Similar Commands

He said to him, “Love the Lord your God with all your heart, with all your soul, and with all your mind. This is the greatest and most important commandment. The second is like it: Love your neighbor as yourself.
(Matthew 22:37-39 HCSB ©®)

Why did Jesus say that loving your neighbor as you love yourself is a command that is similar to the command to love Yahweh with all your heart, mind, strength and stuff?

We love because He first loved us.

If anyone says, “I love God,” yet hates his brother, he is a liar. For the person who does not love his brother whom he has seen cannot love God whom he has not seen. And we have this command from Him: the one who loves God must also love his brother.
(1 John 4:19-21 HCSB ©®)

Love Yahweh, love people. Be awesome.