What Is The Church?

So then you are no longer strangers and aliens, but you are fellow citizens with the saints and members of the household of God, built on the foundation of the apostles and prophets, Christ Jesus himself being the cornerstone, in whom the whole structure, being joined together, grows into a holy temple in the Lord. In him you also are being built together into a dwelling place for God by the Spirit.
— Ephesians 2:19–22

When the word "church" is used in the context of Christianity, there are two related but different meanings.  The word can refer either to the visible church, or the invisible church.  One good reason for this is to differentiate between the nature and members of each one. 

The visible or local churches are led and administered to by fallible men and women, who may or may not all be true believers, and may not all be united in heart, mind, spirit, and doctrine.

 

 

The invisible or universal church, which is  also known as the Body of Christ is comprised only of those truly converted, and are those called by God to be His people.

 

Screen Shot 2016-12-02 at 8.57.53 PM.png
For this reason I bow my knees before the Father, from whom every family in heaven and on earth is named, that according to the riches of his glory he may grant you to be strengthened with power through his Spirit in your inner being, so that Christ may dwell in your hearts through faith—that you, being rooted and grounded in love, may have strength to comprehend with all the saints what is the breadth and length and height and depth, and to know the love of Christ that surpasses knowledge, that you may be filled with all the fullness of God. Now to him who is able to do far more abundantly than all that we ask or think, according to the power at work within us, to him be glory in the church and in Christ Jesus throughout all generations, forever and ever. Amen.
— Ephesians 3:14-21

"We are called to serve the church in the power of God the Holy Spirit.  We, the church, have been made for this task by the indwelling presence and power of God’s Spirit. Yet, we are called not so much to rise up but to bow down. And if we bow down to our Lord, as Paul says in Ephesians, the church will be the church, and our light will pierce the darkness."

R.C. Sproul - What Is the Church?