"But I have this against thee, that thou didst leave thy first love." (ASV)
This passage comes in the midst of Christ evaluating His church. This particular phrase was uttered to the church at Ephesus. Prior to this they are commended for upholding their duties and remaining true to the gospel. They are described as discerning, patient and vigilant. And yet they are rebuked.
I think this shows what Christ values most from us. He is not looking for followers who simply obey the law, do as they are told and uphold the traditions of their faith. He wants more than that from us. His desire is for our passion to be His. He wants a relationship with us.
It is not fitting for a Christian to say they love the Lord, yet continue to chase after the things of this world. "For our God is a consuming fire." (Hebrews 12:29 ASV) When we are truly walking with God and He becomes our first love, we lose sight of all else.
When we are striving toward His will in our lives, we need not worry about the more trivial matters and circumstances. "But seek ye first his kingdom, and his righteousness; and all these things shall be added unto you." (Matthew 6:33 ASV) This is the type of relationship God desires to have with His people.
Have you ever seen someone in the thralls of new love? They walk around with a glow to them. They forget to pay attention to their other friends because all their time is taken in trying to please their sweetheart. Of course, this kind of love doesn't usually last here on earth because they begin to see the flaws in that person they once thought was so perfect.
Loving God can and should be like that. We have the glow of joy around us. We forget the concerns we held only yesterday because they pale in comparison to the God we serve. And we spend our time seeking to please our Lord. The difference is, since He alone IS perfect, there is no disappointment to be had after we come to know who He truly is.