Personally, I refer to my friends as sisters and brothers. Those outside the church that I hold dear have not crossed over that personal relationship with me. I can share good times with them, spend time with them...yet they do not understand the close relationship I have with Christ. They see me as a religious person, rather than one who is in a relationship.
A relationship has stronger ties than friendship. We tend to share intimacy and those deep emotions within a relationship that simply does not occur outside the boundaries of that tie.
Our Lord did not avoid people who did not know his relationship with the Father. In fact He spent time with them, and ate with them. He laughed with them and they enjoyed Him. They saw something different in Him.
That is how we are to be. We are to be a light in a dark world. Yet, we are not to be transformed into the likeness of the world. In other words, be careful. It is easy to suddenly lose the purpose of what you are supposed to be doing, by suddenly taking on the beliefs of people who do not know Christ.
We suddenly forego our time with the family of God, to go to be with people who don't follow Christ and we do what they do. Our mind suddenly comprimises our faith, we dabble in practices outside the word of God. One thing leads to another and suddenly we aren't the light of the world, we ARE the world.
So, I have church 'family' who share the same goals and then I have friends who don't understand those goals. I want to be a light for them by my life. I want them to see Christ in me.
I want to exude the peace I have found. I do not say that I have no problems, but I show them I bring them to the Father. I want them to see joy in me. I want them to see a better way to live life to it's fullest. I want them to feel the Father's love through me.
Yet, I find I am most joyful in the company of the family of God. We share the same name...Christian...one who follows after Christ. We share the same goals...to live for Christ. We share the same issues...the real issues of life. Yet, we go to the same source for our answers. We focus on the answer and not the issue. We may stumble, but our family is there to pick us up.