For this reason, because I have heard of your faith in the Lord Jesus and your love toward all the saints,  I do not cease to give thanks for you, remembering you in my prayers, (ESV)
In the previous fourteen verses of this opening chapter of Ephesians, the Apostle Paul has introduced himself and expounded on the mystery of the Gospel and true saving faith. Now, he speaks directly to the Ephesians about how thankful he is for them. So thankful that he does not cease to give thanks for them, remembering them in his prayers.
Why is Paul so thankful? What was so great about the church at Ephesus? He tells us, in verse 15. He has heard of their faith in Jesus, and their love for all the saints. Their faith was not just talk. It was real. It resulted in loving one another. Remember that the structure of this book of Ephesians is theological and practical. The first 3 chapters being theological, tells us what it means to be a genuine believer. The last 3 chapters being practical, show us how genuine believers behave. Verse 15 is another reminder that what we believe affects how we behave.
I am struck by Paul's reaction to a church's faith. I wonder how many churches in this great land of ours would receive the same admiration from the Apostle Paul. Churches claim to have faith. They claim to believe in God. But, how many of those same churches are full of gossip, divisiveness, and ignoring the needs of their brothers and sisters in Christ? I am afraid that Paul's great thankfulness for the Ephesians' genuineness would not exist for too many of our churches today.
Genuine faith expresses itself in genuine love for one another. The Apostle John puts it this way:
1 John 4:7
 Beloved, let us love one another, for love is from God, and whoever loves has been born of God and knows God. (ESV)
If Paul were to write a letter to your church today, would he say how thankful he was to hear of your genuine faith expressing itself in genuine love for others? If not, what is God calling you to do about it? How can you make changes in your life to love others more?