Your sermon of the week is Separating From Unbelievers by John MacArthur. And yes, in spite of what you see in the lifestyle of the average professing Christian (and even the average pastor), there actually is a biblical mandate for believers to separate from unbelievers.
And for those who will have the typical knee-jerk reaction (who won’t listen to the messages but simply assume what MacArthur is saying), he is not advocating a monastic lifestyle. He simply expounds on the biblical doctrine of separating ourselves from unbelievers including what it is and what it is not.
This is a great refresher about a doctrine that was commonly practiced by the church until recently.