I am often asked why we're planting a new church in Post Falls, an already highly-churched city. In fact, one guy in our core-group was asked by a co-worker why "we think we're better than the other churches." His co-worker's assumption was that we are planting a new church in Post Falls because we think we have better methods, content, gospel-centeredness, or whatever. That's not the case. 

We're planting here because we want to see more gospel-saturation in our area. We understand that the other churches in our city have their own niche in the bigger Story of God. We're in the process of creating another niche. Not so that we can take from someone else's, but so than we can actively participate in creating additional robust niches that lead to more, and more and more . - i.e Making new Disciples. 

Brandon D. Smith articulates this beautifully in his post: 3 Reasons to Plant in Highly Churched Areas on the LifeWay blog. Here's an excerpt:

I often wondered how much more gospel impact could be made if there were just one or two other churches with different models and diverse leaders. Our Jesus is the same, but not everyone comes to him in identical ways. There is room in every context for multiple churches, using several models, all proclaiming the unmatched name of Christ.

The Barna Group says that 3,500-4,000 local churches close their doors every year. If we never plant new churches, we may witness even further troubling numbers. Every church in existence was planted, and every church has its own niche in the bigger story of God. May we never stop until every ear has heard the name of Jesus.
— Brandon D. Smith on the LifeWay Blog.

Read his whole post here.