For some people it is helpful to visually explore what the ekklesia was and should be. Let’s look at what the ekklesia or a portion of the ekklesia would have looked in different contexts:

Illustrations of the pagan ekklesia of Rome in Ephesus and other cities (Acts 19)

A roman ekklesia is seen with a crowd of men of all ages surrounding a tall stone podium where a few are speaking. Many hands in the crowd are raised.
A roman ekklesia is seen with a crowd of men surrounding a tall stone podium where someone is speaking. A few hands in the crowd are raised.
A large group of seated men in white togas surround a stage where someone is speaking. It appears to be an indoor amphitheater.

Illustrations of the ekklesia of Jerusalem gathering in the temple courts (Acts 2)

A crowd of humbly dressed people sit in a circle on the floor of a temple around someone with their head covered. They look relaxed. Religious figures are seen standing afar off.
Huge pillars holding a roof are lined up in two rows and a stream of people can be seen at their bases throughout. The rest of the temple can be seen in the distance.
Large pillars are lined up on either side of of a wide walkway with a few people scattered along.

The above photo is of a replica of the temple courts. Notice how big it was! It makes sense the ekklesia met here because there were more than 3,000 believers in the ekklesia of Jerusalem at the beginning.

Illustrations of a portion of an ekklesia meeting together in a house (Acts 2)

Around twenty people sit around a table with simple food in an ancient dwelling bowing their heads and folding their hands.
A sketch of a dozen people sitting in a loft of an ancient dwelling surrounding someone reading a scroll.
A handful of people relaxing around someone speaking who is holding a scroll. Someone can be seen writing in the foreground. Some have cups in their hands.
About 20 people in a well lit indoor room surround a few who are reading from a scroll.

Since the “ekklesia” includes all obedient believers in a city, the ekklesia will look like the picture above only in cities with a very small number of believers (Romans 16:23). (Of course, this is assuming that everyone who is included attends.) If a city has many believers then the ekklesia will not look like the picture above. When only a portion of the ekklesia gathers, it is not the whole ekklesia. It is a “portion.”

Jesus wants all the believers in each city to gather all-together. It is good for those same believers to gather among the houses, but he does not want all the believers to only gather in small portions because that is not the ekklesia gathering. If a city has 100 believers, they cannot only gather separately in 10 different homes. All 100 believers must also be called to come all-together in one place — since that would be the ekklesia.

Notice also that it doesn’t matter what kind of building the people meet in. It can be a big building or a small home. It depends on how what believers are included (all versus a select few). The important thing is that the believers are both meeting from house to house and all-together in one place. If there are so many people that they can only meet at a large field or a large building or a large court like those in Jerusalem, then so be it. It’s such a blessing when all God’s people in a city come together in one place!