To answer such a question properly and honestly, it would first be necessary to try and clear the field of all the brush and weeds that would prevent us from understanding what God had to say about it. As early as 180 AD, Clement of Alexandria was correcting the misunderstanding that you can "go to church." He had to mention that the church is not a place or building. Since then we have another 1800 years of misconceptions. The church is not a congregation (from a collection of cattle); it is not a denomination (the Bible calls those sects and divisions); it's not a parachurch organization (a unique creation of religious man) - so it's not what most people conceive it as.
If you would look at Acts 19 you would find that the citizens of Ephesus rioted and gathered in the local theater. They were called an "assembly" - and that is where the meaning of church came from. Church is the translated word for "ekklesia", which means "called out assembly", and refers to the citizens of a Greek polis (city-state) that are called together to discuss and conduct city business. It happened to be this word that was appropriated by the first Christians to describe their gatherings together. The English word "church" is derived from the Greek word "kuriakos" which means "the Lord's." So the word meaning "the Lord's" is used as the translation for the word meaning "an assembly."
What does the Bible tell us?
Church is the people
In 1 Thessalonians 1:1 Paul says
"... unto the church of the Thessalonians which is in God the Father and in the Lord Jesus Christ..."
This epistle was addressed to Thessalonian residents who were in God the Father, and the Lord Jesus Christ, i.e. to the Christians in Thessalonica. It wasn't an assembly of all the Thessalonians, but only of those that were called-out from the mass of the residents, the saved ones. They gathered to be together around Christ and for His sake.
In 1 Corinthians 1:2 this is advanced to show us that the church is
"...the church of God which is at Corinth...called saints..."
Here it is those that He called out of the general population in the city of Corinth to be His. These children of God meet together. If you look closely at Scripture you will see that each church is either all the Christians that reside in the same city [the real local church*], or all Christians considered as a whole [the so-called universal church]. If we understand these truths, then we can ponder the question, "What is the purpose of the church?"
What is the purpose of Church?
In Ephesians 3:10,11 Paul says,
"To the intent that NOW the manifold wisdom of God might be made known by the church to the principalities and powers in the heavenly places, according to the eternal purpose which He accomplished in Christ Jesus our Lord."
We see that God had a purpose in eternity past that would be accomplished in Jesus Christ. This purpose that transcends time, would show the many aspects of His wisdom to those that would look and see ("which things the angels desire to look into"). It is to be seen NOW by the church! This is described in the Scriptures under the phrase of a "mystery", of which there are at least 7 in the Bible:
"This mystery among the Gentiles; which is Christ in you, the hope of glory." (Colossians 1:27) "The mystery of his will...he might gather together in one all things in Christ..." (Ephesians 1:9,10) "..ye may understand my knowledge in the mystery of Christ...(Ephesians 3:4) ...that the Gentiles should be fellow heirs, and of the same body...(Ephesians 3:6) ...this is a great mystery: but I speak concerning Christ and the church." (Ephesians 5:32) "raised from the dead...set him at his own right hand...far above all principality and power... and hath put all things under his feet, and gave him to be head over all things TO THE CHURCH, which is his body, the fulness of him that fills all in all."(Ephesians 1:20-23)
Without explaining all of those verses, let me summarize the PURPOSE of the church: The church is to show the wisdom of God for all to see, by being so united to the Lord Jesus that it serves as His body. It is to show forth His life and character and administer His authority, as it receives its life from Him and its direction from Him as its Head. Thus, God will be glorified by manifesting Himself through His redeemed ones, who bare His image and exercise His dominion. Only thus can His fulness be EXPRESSED.
With this as the purpose of the church, "how should we then live?" The answer is obvious, it is now a matter of application.
In Christ, Lawrence Howie
*Some see any gathering of Christians as a valid "church" and use Romans 16 as a defense of that belief, by showing that several groups seemed to be mentioned in that passage - therefore, could there not be many "churches" in Rome? The problem is that Rome had up to 30 differently meeting groups in the city of Rome, but saw themselves as the one only church [a single church-the one assembly] in Rome until about 250 AD. When the first divisions came, then the defense that "our" group was a church also started being taught. Instead of confession and repentance, there was defense, excuse, and further splitting of the seamless robe of the Lord's spiritual body. May the Lord forgive us! Let us be part of the solution and not the perpetuation of the problem.