In the Scriptures the ecclesia (the ones called out and assembled together) is likened to a growing human body. Acts.2:47 tells us that, “the Lord added to their numbers”. It’s a good idea to know what the New Testament ecclesia really is; as against what many think it is!
What is the “Ecclesia”?
Here are some bible answers:
i. (Heb 10:25 NRSV) not neglecting to meet together, as is the habit of some, but encouraging one another, and all the more as you see the Day approaching.
ii. Eph 2:19-22 NRSV) So then you are no longer strangers and aliens, but you are citizens with the saints and also members of the household of God,  built upon the foundation of the apostles and prophets, with Christ Jesus himself as the cornerstone.  In him the whole structure is joined together and grows into a holy temple in the Lord;  in whom you also are built together spiritually into a dwelling place for God.
iii. (1 Cor 12:27 NIV) Now you are the body of Christ, and each one of you is a part of it.
What did Jesus say?
The ecclesia would have the keys of the kingdom.
The ecclesia would have a binding ministry.
The ecclesia would have Jesus in the midst of them.
The gates of hell would not overcome it.
Read Matt.16:18-19 Matt.18:15-20.
Jesus also said: He would build His Ecclesia.
Two ideas about the Ecclesia
i. The spiritual universal oneness of God’s people:
(Eph 1:21-23 NIV) far above all rule and authority, power and dominion, and every title that can be given, not only in the present age but also in the one to come.  And God placed all things under his feet and appointed him to be head over everything for the ecclesia,  which is his body, the fullness of him who fills everything in every way.
(Col 1:18 NIV) And he is the head of the body, the ecclesia; he is the beginning and the firstborn from among the dead, so that in everything he might have the supremacy.
ii. The ecclesia local (each and every one part of the spiritual ecclesia).
(2 Cor 8:1 NIV) And now, brothers, we want you to know about the grace that God has given the Macedonian ecclesiae.
Be very clear that the church means ecclesia, the people, not buildings of any sort.
These references will help you list the basic steps needed to become a member of the universal spiritual ecclesia and to go on with God as a member.
1. Acts 2:38
2. Acts 8:37
3. Acts 2:38, 41
4. Acts 2:38-39
5. Acts 2:42 (look for four steps in this verse)
I hope that these four studies have started you on the way to abundant life in Christ. Very simply the aim has been to introduce you to three great ideas.
1. Our wonderful Lord God.
2. The Ecclesia, His body.
3. His words of love to us.