Hebrews 10:24-25 (NKJV)
And let us consider one another in order to stir up love and good works, not forsaking the assembling of ourselves together, as is the manner of some, but exhorting one another, and so much the more as you see the Day approaching.
When a person is saved, it is a matter between him and God. Even though it is an individual response to the calling of God, usually there will be a number of family and friends who will rejoice in the miracle that is the new birth. But it is possible and actually common that an individual in the privacy of his bedroom will kneel beside his bed and ask Jesus Christ to become his Lord and Savior. Regardless, a new birth, whether it is physical or spiritual will always be into a family. The church is the body of Christ, the family of God.
So even though we are saved individually our growth is a corporate matter. This verse tells us to encourage each other in love and ministry. It tells me that I can't have church by myself. When we come together for the purpose of worship and fellowship, we are building each other up.
Here is the intriguing part; we are to concentrate on this corporate activity more and more as we see the Day approaching. What day is that? It is the second coming of Christ. It is the consummation of all things into God's final plan for this earth and its inhabitants. Apparently it is important for us to increasingly build each other up as these end times approach. Perhaps it is because there will be opposing influences seeking to limit the influence of the church.