Paul, an apostle of Christ Jesus by God’s will: To the faithful saints in Christ Jesus at Ephesus.Ephesians 1:1 HCSB

The saints in the church of Ephesus were faithful during the time of Paul, 60-61 AD, but by 81-96 AD when John wrote revelation they had lost their first love. So what happened in 20 years to the Church in Ephesus to go from faithful saints to having lost their first love? Growth, spiritual influence, and accountability are some factors that might have steered the church away from Jesus. 

Growth in the church causes a less personal church. When the church is small every member has connections to the other members it may be family ties, a co-worker, or family friends. The leadership of the church is more connected to the individual members and the pulse of the church can be more unified. They can help each other to be more faithful to Christ. Now when a church reaches Mega status a family may get lost among the crowd because they are only acquainted with one or two other people. The leadership now has to appeal to the larger crowd and is less connected to the individual. The megachurch has a harder time keeping the body as a whole faithful to Christ.

From Him the whole body, fitted and knit together by every supporting ligament, promotes the growth of the body for building up itself in love by the proper working of each individual part.

Ephesians 4:16 HCSB

https://bible.com/bible/72/eph.4.16.HCSB

Spiritual influence is the biggest influence in our Faithfulness to Christ. The people we are following are imperfect but are they pointing you to Jesus and His word while at the same time striving toward Jesus? Or are they pointing toward the world while kinda sounding like Jesus and have no desire to be sanctified by the Word of God and His Holy Spirit? 

My sheep hear My voice, I know them, and they follow Me. I give them eternal life, and they will never perish — ever! No one will snatch them out of My hand. My Father, who has given them to Me, is greater than all. No one is able to snatch them out of the Father’s hand.

John 10:27‭-‬29 HCSB

https://bible.com/bible/72/jhn.10.27-29.HCSB

Just as I also try to please all people in all things, not seeking my own profit, but the profit of many, so that they may be saved. Imitate me, as I also imitate Christ.

1 Corinthians 10:33-11:1 HCSB

https://bible.com/bible/72/1co.10.33.HCSB

https://bible.com/bible/72/1co.11.1.HCSB

Accountability within the leadership and the body is what can keep Jesus as the first love and keep us faithful to Him. So does accountability look like in the church settings? No one person serves in the body of the church by themselves! My teaching, rebuking, correcting, and training are to be subjected to the Leadership I submit under and the Bible and I hope that if I speak out of place or teach the Truth falsely then I should be corrected by the same leadership I submit under. Everyone is to answer to someone else here in the flesh and God. When someone speaks under no accountability they are at risk to only speak what tickles their ears and not the Truth of the word of God. Most importantly I will, now and later, have to answer God how I have handled His Word in my life and how I have taught others to do the same.

For none of us lives to himself, and no one dies to himself. If we live, we live for the Lord; and if we die, we die for the Lord. Therefore, whether we live or die, we belong to the Lord. Christ died and came to life for this: that He might rule over both the dead and the living. But you, why do you criticize your brother? Or you, why do you look down on your brother? For we will all stand before the tribunal of God. For it is written: As I live, says the Lord, every knee will bow to Me, and every tongue will give praise to God. So then, each of us will give an account of himself to God. Therefore, let us no longer criticize one another. Instead, decide never to put a stumbling block or pitfall in your brother’s way.

Romans 14:7‭-‬13 HCSB

https://bible.com/bible/72/rom.14.7-13.HCSB

Not many should become teachers, my brothers, knowing that we will receive a stricter judgment,

James 3:1 HCSB

https://bible.com/bible/72/jas.3.1.HCSB

I do not know what caused the falling away of the church in Ephesus, but I can make sure I am holding and teaching the commands of the Bible. The example of Ezra 7:10 is a good guide to keep us faithful to Jesus.

Now Ezra had determined in his heart to study the law of the Lord, obey it, and teach its statutes and ordinances in Israel.

Ezra 7:10 HCSB

https://bible.com/bible/72/ezr.7.10.HCSB

Ezra first determined to study the Bible that he had. Then after He had taught himself he began to follow it. And only then did he begain to teach it.

He also appointed 12 — He also named them apostles — to be with Him, to send them out to preach,

Mark 3:14 HCSB

https://bible.com/bible/72/mrk.3.14.HCSB

Jesus also trained His 12 disciples to do the same. First, they were to spend 3 years with Jesus, learning and submitting their lives to Jesus and then going out after they had received the power of the Holy Spirit to preach.

And look, I am sending you what My Father promised. As for you, stay in the city until you are empowered from on high.”

Luke 24:49 HCSB

https://bible.com/bible/72/luk.24.49.HCSB

But you will receive power when the Holy Spirit has come on you, and you will be My witnesses in Jerusalem, in all Judea and Samaria, and to the ends of the earth.”

Acts 1:8 HCSB

https://bible.com/bible/72/act.1.8.HCSB