1"To the angel of the church in Ephesus write:
These are the words of him who holds the seven stars in his right hand and walks among the seven golden lampstands: 2I know your deeds, your hard work and your perseverance. I know that you cannot tolerate wicked men, that you have tested those who claim to be apostles but are not, and have found them false. 3You have persevered and have endured hardships for my name, and have not grown weary. 4Yet I hold this against you: You have forsaken your first love. 5Remember the height from which you have fallen! Repent and do the things you did at first. If you do not repent, I will come to you and remove your lampstand from its place. 6But you have this in your favor: You hate the practices of the Nicolaitans, which I also hate. 7He who has an ear, let him hear what the Spirit says to the churches. To him who overcomes, I will give the right to eat from the tree of life, which is in the paradise of God.
Verse 2-3 shows that what this church is doing is clearly good and worth praising. Even in the face of persecution they have not grown weary and in the midst of false teachers and teachings, they have stayed true to the Truth and not allowed outside influences to tear down the walls of righteousness.
However, when we look at verse 4, the Church in Ephesus is being rebuked for forgetting why they are doing ministry. This church must have been doing ministry well, but they have lost sight as to why they are doing it. The reason why the church exists is none other but to show the love of God. That "first love" is in reference to the commitment to help and serve others and the Church of Ephesus is doing ministry without being rooted in Christ's love.
In conclusion, this passage is rebuking the Ephesians attitudes and reminding them that what they are doing in the name of God, must be done in love.
[answered by Pastor KJT]