I have heard my Dad (Zac Poonen) use this illustration to show the difference between the Old Covenant ministry of the Holy Spirit and the New Covenant ministry of the Holy Spirit: In the Old Covenant, man's heart was like a cup with a lid on it (like the veil that closed up the most holy place in the Jewish temple). The Holy Spirit was poured out on this closed lid of the cup and He flowed over it in rivers of blessing to multitudes around - as He did through Moses, John the Baptist, etc.
But in the New Covenant, the lid is removed (2 Corinthians 3:12-18). This was symbolized by the veil in the temple being rent when Jesus died, and the way into the Most Holy Place being opened up. Now, when the Spirit is poured out, He fills the cup first - cleanses the believer's heart first - and then flows out "from his innermost being" in blessing to multitudes, as Jesus explained in John 7:37-39 . This is how the New Covenant Church is built.
If we are still trying to use the Holy Spirit only to preach to others, then we will only build a Congregation or a Club. But if we allow God to fill us and shed abroad His love in our hearts first of all, then He can flow from our innermost being to others. Then we will build the Church with others who also have the same spirit of fellowship. Love for God and for others will overflow from our hearts, and true unity of the spirit will be built through each of us taking up the cross.
In reality, the true Church is built up primarilywhen we are away from each other. It is not built only when we gather together at our Sunday meetings. Yes, it is built there through the gifts of the Holy Spirit. But, it is built even more so when we are away from each other. When we are being tempted in some way - to be dishonest, or to be angry, or to lust with our eyes, etc. - that's where you prove whether you are part of Jesus' Church. In these temptations, if we take up our cross, die to ourselves, preserve our devotion to the Lord, and resist sin, then we walk in the light and have fellowship with the Lord. Then, when we meet together with each other, we will have real fellowship with each other (I John 1:7).
Colossians 2:2 speaks about our hearts being "knit together in love". I cannot knit myself to others, in love. Only the Holy Spirit can do this work of knitting our hearts together. If, however, I try to knit my heart to yours in some human way, by giving you gifts, or by spending time with you, etc., I will only build a Club. But God says, "Just die to yourself". When I do that, the Holy Spirit will do the work of knitting my heart in an invisible, supernatural way, with the others among whom he has placed me in a local church, who are also dying to themselves.
Our fellowship will then become sweet - not because we believe the same doctrines or sing the same songs, but because we have both fallen into the ground and died to our Self-life. We come into fellowship with each other, thus, through the Holy Spirit.
Any unity that we have, without dying to Self, will only result in friendship, and not true Christian fellowship. Fellowship is a spiritual thing, but friendship is an earthly thing.
The people in the world have friendship. The members of many worldly clubs have a lot of close friendship with each other and care foreach other deeply. But they can never have true fellowship - because that is a spiritual work that only the Holy Spirit can do in our lives. When God sees any child of His "bearing the dying of Jesus in his body ", He rewards him by giving him something more of "the life of Jesus " (2 Corinthians 4:10,11). It is this "life of Jesus" within two believers that brings true fellowship between them. And with such people God builds His New Covenant Church.
When I began to see these truths, I stopped asking the Lord, "Lord, where are the people who want to build Your true Church?" I realized that God would find them and bring us together - if I myself was first willing to fall into the ground and die. If I refused to die, then God would not bring them to me.
Trying to find wholehearted believers around us is like trying to find "needles in a haystack". We could spend many years searching in the pile of hay for those tiny needles in that pile; and perhaps find one needle after many years of effort. But the Lord says, "Don't waste your time looking for those needles. I know where they are. Just fall into the ground and die to yourself." Then the life of Jesus in you will become such a powerful magnet, that it will draw those "needles" (wholehearted disciples) out" (John 1:4,12:32).
Other believers who are also seeking to live a godly life and to build the New Covenant Church will be drawn to you and to the message of the cross that you proclaim. That is God's way. He brings the wholehearted ones to us. "All whom the Father gives Me will come to Me", Jesus said in John 6:37. And the Father will do the same for us too. That is how we build the New Covenant Church.