What is being lost sight of in some fundamental churches?

Les explains that this whole matter of separation is being lost sight of even in some of our more fundamental Bible teaching and preaching churches. As a result, the world can't tell a Christian when they see one, and Christians can't tell a Christian when they see one. Les says we have lost this whole concept of separation, and we are to be different. He clarifies that being separate does not mean putting our nose in the air or having no dealings with the world; we are in the world but not to be of it. He connects this to 2 Corinthians 6:17, where God says, 'I will receive you,' and the invitation to come out from among that ungodly set of circumstances and be separated. This is not a condition on salvation, but as a believer, under grace, God never says 'you will or else'; it is always an appeal, and it is left up to us.