"Then when they are exiled among the nations, they will remember me. They will recognize how hurt I am by their unfaithful hearts and lustful eyes that long for their idols. Then at last they will hate themselves for all their detestable sins. They will know that I alone am the Lord and that I was serious when I said I would bring this calamity on them." -Ezekiel 6:9 & 10
A while back a fairly well-known rock band came out with a song called, "Love Hurts." The song rings with a lot of truth - love, as we know it, hurts sometimes.
In a similar sense, our relationship with God is a lot like a love story. In the New Testament, God calls us (the church, the body of believers), His bride, and Jesus is the bridegroom. It's an analogy of how Jesus paid the price for our sins, and invites us to live with Him in eternity. It was out of His love for mankind that He made such a sacrifice, and overcame our decision to sin.
Even though we may think of God as unwavering and unstoppable, so strong and mighty, and though He may be immune to any harm, that is not the case with His heart. He cares so much for mankind, that when we do things to turn away from Him, He is hurt.
This is referenced by the verse above, "They will recognize how hurt I am by their unfaithful hearts and lustful eyes that long for their idols." The story between God and mankind was the original love story, with God getting rejected many many times - outside of His perfect will for the world.
In our own lives, sometimes it's good to think about any areas in which we might need to repent to keep the line open between God in ourselves. Frequently asking Him, "God is there anything I've done that has hurt Your heart?" is a good place to start.
We want to be sure we are good with our Heavenly Father, at all times.