To the angel of the church in Ephesus write:
The One who holds the seven stars in His right hand, the One who walks among the seven golden lampstands, says this:
I know your deeds and your toil and perseverance, and that you cannot endure evil men, and you put to the test those who call themselves apostles, and they are not, and you fond them to be false; and you have perseverance and have endured for My name's sake, and have not grown weary.

But I have this against you,

that you have left your first love.

Remember therefore from where you have fallen, and repent and do the deeds you did at first; or else I am coming to you, and will remove your lampstand out of its place--unless you repent.
Yet this you do have, that you hate the deeds of the Nicolaitans, which I also hate.
He who has an ear, let him hear what the Spirit says to the churches.  To him who overcomes; I will grant to eat of the tree of life, which is in the Paradise of God.  Rev. 2:1-7

When Christ really captivates, everything happens and anything can happen.  That is how it was with Paul and with these people (the people at the church in Phillipi).  Christ had just captivated them.  They had no other thought in life than Christ.  They may have had their businesses, their trades, their professions, their different walks of life and occupations in the world, but they had one all-dominating thought, concern and interest -- Christ...
There is no other word for it. He just captivated them. And, I see, dear friends, that that -- simple as it may sound -- explains everything.  It explains Paul ... it explains these believers, it explains their mutual love. It solved all their problems, cleared up all their difficulties. Oh, this is what we need! If only you and I were like this, if we really after all were captivated by Christ! .. After all, nine-tenths of all our troubles can be traced to the fact that we have other personal interests influencing us, governing us, controlling us -- other aspects of life than Christ. If only it could be true that Christ had captured and captivated and mastered us, and become -- yes, I will use the word -- an obsession, a glorious obsession! When it is like that, we are filled with joy. There are no regrets at having to "give up" things. We are filled with joy, filled with victory.
There is no spirit of defeatism at all. It is the joy of a great triumph. It is the triumph of Christ over the life ... but, oh, we need the captivating to wipe out our selves -- our reputations, everything that is associated with us and our own glory -- that the One who captivates may be the only One in view, the only One with a reputation, and we at His feet. This is the gospel, the good news -- that, when Christ really captivates, the kind of thing that is in this letter (Philippians) happens, it really happens! Shall we ask the Lord for that life captivation of His beloved Son.

T Austin Sparks

as quoted in Insurgence (by Frank Viola) 

And, here we have the church at Ephesus.They were doing all the "good things," all the "good works" that we are sent to do as Christ's representatives.  But they had lost the love that was intended to motivate and direct those works.  Were those works still "good?"  Yes, but did those works still represent Christ?  Did those good deeds still bring His light to the world?

Jesus warns that if they do not repent, their lampstand, their representation of Christ in the world would be "removed" from its place.  They would no longer be His light.  

Oh, for a heart that is captivated with Christ, that serves from that love and because of that love.  Oh, for a heart that remains true to that "first love."