How to respond to a stake driven into your back yard-

Recently the Mormon Church started building a huge stake center right accross the street from one of my home town’s largest and most respected Evangelical churches. This church is positioned on the top of a hill right in the middle of an upper middle class neighborhood.
The new Mormon stake is the biggest and the most beautiful that I have ever seen. Whether we like to admit it or not; competition is at play. This is like a Burger King being built accrossed the street from a McDonald’s.
Obviously, the two group’s theologies are diometrically opposed to each other. My question as a Christian, and as someone in ministry, is how does the Evangelical church respond to the false center of worship being built accross the street.
Does the Evangelical church ignore and ostrisize this new congregation? Do they welcome them as neighbors and work together with them to meet the needs of the community? Do they in some way publically display to the community that their new neighbor is a cult?
Can light and dark work together to achieve good for a community? These are the kind of questions my friends at the Evangelical church are having to address. Pray that Gid will show them the answers.