Then of course two Christians, maybe the only Christians in a place of work, could be longstanding co-workers. It's hard to legislate against being on reasonably friendly terms with someone with whom one has something in common. I'm also a strong believer in maintaining proprieties; for example, if both want to attend a Christian rock concert or whatever, it's best to go as part of a group.
I agree with you, farouk, except that this thread isn't about being "reasonably friendly" with people of the opposite sex. Really, as Christians, we should be reasonably friendly with everyone, unless shown good reason not to be.
But, the topic at hand is "My best friend - an opposite sex". There is a big difference between those we are friendly with and our "best friend".
Going back to my husband's friend who cried on his shoulder and was given an encouraging hug... well, if my best friend (who is a woman like me) was going through the same thing, I'd let her cry on my shoulder and I would hug her too. The falling apart of a marriage... or the serious illness of a child or the death of a parent... all these are situations where we as human beings rely upon each other and being given physical responses, (being held, shoulder to cry on and hugs) are how we are sustained through these bad times.
The problem is... when the two friends are of the opposite sex, especially when both are married to others, that physical contact is at best inappropriate and moreover, opening both up to temptations and leads that Christians should flee from.
As to questdriven's observations:
Just seems rather harsh to break off a friendship abruptly like that. Friendships are based on mutual trust and respect as well.
I agree with not being alone with them, however. That is a danger and I understand that.
I agree that a friendship needn't be broken off abruptly. Never being alone with each other is definitely a key. Another big part of this is for the spouse that is the same sex as the friend to become friends as well.
However, it's a sad story that's told over and over, couples who are friends and do things as couples and then find that two out of the four were having an affair. It's not logical or even intelligent to ignore the eons established fact that people, even "good Christian people" fall into temptation and sin.
To me, it was a big red flag that Steve and his friend had physical contact (albeit not sexual in any way) and Steve respected my (his wife's ) wishes to never be alone with her again. And, lo and behold, once it was clear that from then on, all time spent together would include at least me, if not her husband and child as well... she never took us up on the offer.
It's possible for friends of the opposite sex to remain friends after one or both marry... but it's my opinion it's not possible or even desirable for two people of the opposite sex to remain "best friends" after one or both marry.
Really, if one's spouse isn't the best friend of the opposite sex one can have... there's something wrong.