This is one of the most basic things that we are taught in Sunday school about God. But we so often try to balance that with other things we see in the Bible about God and we forget that this is not just a description of His character but it is the essence of who He is.
What this means is that Love defines who God is and everything about Him. He is a judge but being a judge comes out of the fact that He is love, He is creator but that comes out of the fact that He is love. He is a loving judge and He is a loving creator. It is the same too for other characteristics that we see in Him they come out of the fact that He IS love.
As someone who has always known God to be around in my life and has grown up in churches I know lots of facts like God is love, Jesus is fully God, God is a God of justice, Jesus and the Father are one and other such things but it is sometimes difficult to really experience the truth of these things. If God is a god of Justice how does that tie up with the picture of Jesus allowing the woman caught in adultery to go free, how does that tie up with God allowing any of us to go free because of someone elses actions. When we see that God IS love and see that other things come out of that then it starts to make so much more sense and is so much more beautiful. I really want to worship a God who loves so much He can take on the pain of forgiving us willingly, I can worship spontaneously a God who can set people free because He loves them.
Why is it that we tend to see Jesus as being love but then see God the Father as being judgmental? It is sometimes so easy to think of Jesus as being a nice comfortable 'person' to be with but God as being somewhat more distant. If Jesus is the "exact representation" of the Father shouldn't this separation in our minds be removed?