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 is constant, but what about instead of thinking "God is constant = God is always in love with us", why don't we think "God is always in love with us = God is real, He is there, unchanging, unmovable, constant." I think a lot of the time people will cloud their minds with ideas but not really developing a deeper heart for what they really mean. I know God is there, I know He is unchangeable, I know about His law and His sovereignty, and about how He cares for us enough to send His one and only Son to die for us. But when the ideas move into more than just beliefs, it as if life brightens with all the meaning that it is created to be with. 

Love is constant, it was there before we were born and there is nothing we can do that will make Him love us less. Yes, we can make Him angry, with a righteous anger, but it never demeans His love for us. That is something my heart can rest in.