What does it mean to be Church?

Here's my current notes for my third and final talk at the SBM weekend away. I'm working towards a missional ecclesiology - another fashionable but fraught topic. I've had a read of Tim Chester & Steve Timm's book Total Church. Interesting.
As ever, feedback highly appreciated.
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Church is the family of people who have been redeemed from sin by Christ’s death and resurrection. Their defining characteristics are faith and repentance: they trust Jesus to be forgiven, and they have turned from sin, to follow Jesus.
On the one hand, the church is a foretaste of the end. In heaven, we’re going to be gathered around Jesus, being ruled by him, worshiping and praising him—which is what we should be doing on earth. Heaven is an eternal church service.
But we’re not in heaven yet. The church is still in the world—a world in rebellion against the God we serve. While we’re in this world, we must be characterised by two things: repentance, and evangelism.
Although we’re not of the world, we’re from the world—we once were sinners; now we’re redeemed, saved. Having come from the world, we all have sinful habits and behaviours that still hang around. Many of them will be cultural; many will be ‘blind spots’ to us. This is why we need the church—God’s community. The church is a workshop for Godliness, where we confess our worldliness to each other, and call each other to repent of it. For the church to be that, it must be both safe and challenging: safe enough so people can honestly confess their sins and failings; but also unequivocally challenging people to repent of those sins and failings. Hmmm—that’s exactly what Jesus did. “I do not condemn you… [but] go and leave your life of sin” (John 8:11).
This repentance will itself be evangelistic. Godly relationships will themselves testify to the God we serve. People will see how we’re different to the world, different to worldly culture. They’ll see how we’re constantly confessing, challenging, and repenting—and they’ll be threatened by it. The sins we’re confessing and repenting of will be sins they’re living in. As we confess and repent, they’ll feel judged; and they’ll hate us for it. But we can’t leave it at internal church relationships. Church is dynamic because the gospel is dynamic, and the gospel is dynamic because God is dynamic (ref talk 1). Every church should be outward focused, seeking to expand God’s kingdom as much as possible, because our God is outward-focused, and seeks to expand his kingdom as much as possible.