Hi, Tanaya.
The New Testament was originally written in koine Greek, so, every time that you read the word "church" in the New Testament, you are reading an English translation of the Greek word
ekklēsia. The word
ekklēsia is a compound word which is formed from two other Greek words,
ek and
kaleō.
https://www.blueletterbible.org/lexicon/g1577/kjv/tr/0-1/
The word
ek means "out of" or "from".
https://www.blueletterbible.org/lexicon/g1537/kjv/tr/0-1/
The word
kaleō means "call" or "bid".
https://www.blueletterbible.org/lexicon/g2564/kjv/tr/0-1/
With this in mind, the word "church" or
ekklēsia literally means "those who have been called or bidden out or from".
From where has the "church" been "called out" or "bidden from"?
According to the Bible, the "church" or Christians have been called out of darkness and into God's marvelous light by the gospel of Jesus Christ.
2 Corinthians 4:6
"For God, who commanded the light to shine out of darkness, hath shined in our hearts, to
give the light of the knowledge of the glory of God in the face of Jesus Christ."
1 Peter 2:9
"But ye
are a chosen generation, a royal priesthood, an holy nation, a peculiar people; that ye should shew forth the praises of him who hath called you out of darkness into his marvellous light:"
In other words, the "church" is not really a particular sect or denomination. Instead, it is made up of believers all over the world who have truly been called out of darkness and into God's marvelous light.
On another thread, I gave you a link to a movie about William Tyndale who is highly responsible for the English translation of the Bible. When Tyndale was translating the Greek word
ekklēsia into English, he deliberately translated it as "congregation" instead of "church" because he knew that people would wrongly associate the word "church" with a particular sect or denomination. In his day and age, the prevailing sect or denomination was Roman Catholicism. Here is a link to that movie, again. If you watch just a few seconds of it, from 28:48 to 29:24, then you will see this depicted there:
Also, in a figurative sense, Christ's "church" is likened to a body in scripture, and Christ is likened to the head of the body.
Ephesians 5:23
"For the husband is the head of the wife, even as Christ is the head of the church: and he is the saviour of the body."
Colossians 1:18
"And he is the head of the body, the church: who is the beginning, the firstborn from the dead; that in all
things he might have the preeminence."
In the same way that your thoughts, or mind, or head governs the activities of your body, so ought the church be governed by the mind of Christ (check out my username). The only way that you are ever going to be able to properly determine exactly what Christ's mind is on any given topic is to read the word of God, the Bible, for yourself because Christ's mind is revealed to us throughout its pages. If you just run to a particular sect or denomination instead, then they are inevitably going to indoctrinate you into their particular set of beliefs. God has not left you alone in this quest for truth or in your quest to truly understand Christ's mind on any given topic. Instead, if you are a Christian, then you have been indwelt by the Holy Spirit, who is called both "the Spirit of truth" and "the Spirit of Christ' in scripture, and he will help you to understand exactly what Christ's mind is if you simply pray and ask him for guidance and assistance.
Basically, what I am trying to say to you here is that the "church" is not really a particular sect or denomination, but rather the worldwide congregation of called out believers. To that point, like you said, wherever two are three are gathered together in his name, they are gathering as the "church".