Christians hide from culture and from the world. The church becomes a refuge rather than...well a church! We become like Tolkien's Hobbits. We expect non Christians to meet us on our own terms, not on theirs, we don't take any time to think about what unsaved people are thinking about. There are some positives to this approach, at least Christians are distinct from the world. In some places the only way Christians can be distinct is to take more radical steps than the great moral majority. At least Christians are protected...but probably at the expense of effective evangelism. We've tried to be monks before, and it's not worked.
To make sure that churches don't become monasteries we become over engaged. Not wanting people to think that Christian's are weird we watch the same tv shows, go to the same films and listen to the same music. We don't think about how the Gospel effects any of those things, we don't look to see the truth of the Gospel in our culture, we just turn our minds off, put our Bibles away and watch. Instead of having a mind renewed by scripture, we have a mind bathed in Christ minimizing culture. From the outside looking in the church looks no different. In the west our danger is not so much persecution as jellification. We need to be interacting, but not like this.
Some people are clearly gifted in this area. The church needs people who can really engage with culture, who can do apologetics and subvert and persuade people that the Gospel is true. God has given has these people. So shall we just leave it to them? Buy Tim Keller's books and say what he says? Well, that might not be a totally bad thing, but the Bible doesn't seem to leave it just up to the eyes of the body to do this work. We are all called to share the Gospel, so we all need to be aware of how to do that in a relevant manner.
The problem, as Paul Huxley said, is that sometimes we end up running before we can walk. We try to engage but end up being assimilated in thought and deed to whatever is around us. We need to protect ourselves, but we need to be out in the front line. We need to armour ourselves with the word of God, the Gospel of peace, the sword of the Spirit, the helmet of salvation. We need eyes like Edwards' or we risk our hearts shrinking as they soak in sitcoms. The the Lord won't attract us, and the Great Commission won't appeal to us.
We need to fight and run. We need to move quicker than we can. We need to feed our minds with the word, present ourselves as a living and reasonable sacrifice, and engage and persuade. We need to make sure we're doing all of these things.