It's a provocative argument advanced by John Schroeder in this blog post. But I think that his point is well-taken. Some people aren't ready for the kind of vulnerability to God and empathy for others that is central to church culture. They're not prepared for the intimacy with God and others that's a part of Christian life which Christians, when we're tuned into God, take for granted.
Of course, in the face of the fears of non-churchgoing friends, we Christians aren't, in Jesus' phrase, to keep our light under a bushel basket. A relationship with Jesus Christ is the very best thing that any human being can have. Things like love, compassion, and friendship will cause Christians to want to share that relationship with others, in spite of the prospect of rejection. Just because some people aren't ready yet for the kind of love that can be found in Christ's Church doesn't mean that we shouldn't love them enough to let them know that the welcome mat is always out for them.
Like Philip in the New Testament, who, when asked by his friend Nathanael if anything good could come from Nazareth, Jesus' hometown, we're called to tell our friends, "Come and see."