Is it right that my husband asks me not to be friends with one of my
girlfriends just because he "believes" she doesn't like him? I have told
him many times she doesn't even make comments about him. My husband and I
have been separated and my friend was there for me. My husband is a very
insecure man. It seems he wants to control every aspect of my life just
because he is insecure. We are both Christians so I believe he is sinning,
but I don't know how to reprove him. He is very bitter and unkind about my
relationship with her. I've known her for about eight years and we are more friends at work than outside of work. My husband also works with us, so when he sees us together it makes him mad. He tells me he has so much bitterness toward me because I'm friends with someone who doesn't like him. I told him that she has never mentioned to me since our separation how she feels about him. We both had friends that took sides when we weren't together and I never expect everyone to like me. My friend and I do not discuss our marriage. We talk about religion or her life or my pregnancy and kids. We walk most days for a half hour at work and that's about it. I know I'm supposed to be submissive. I truly believe he is sinning for him to act this way especially at work.
What you are describing is jealousy, which means wanting to possess something or someone exclusively. The word can be used in a good sense when what is wanted really does belong to someone. For example, a husband would be properly jealous if someone tried to steal away the affection of his wife. "Set me as a seal upon your heart, as a seal upon your arm; for love is as strong as death, jealousy as cruel as the grave; its flames are flames of fire, a most vehement flame. Many waters cannot quench love, nor can the floods drown it. If a man would give for love all the wealth of his house, it would be utterly despised" (Song of Solomon 8:6-7). A sinful jealousy is when a husband want so possess all of his wife's attention, such as forbidding her to see or talk to anyone else.
Paul stated, "Love is patient, love is kind and is not jealous" (I Corinthians 13:4). One of the characteristics of true love is the confidence one has in the one we love. When I love my wife, I don't have to worry about someone stealing away her affection for me because I know that it is there. If someone tried to come between my wife and I, then I would step in to protect what is mine.
The core of your problem is that your husband has lost his confidence that he truly holds your affection. I don't know if it existed before your break up, but it is obvious that it exists now. His lack of certainty is manifested in his jealousy toward your friend, but this is just a symptom and not the cause. The separation caused damage to your relationship. It will take time for the wound to repair.
I don't suggest that you stop talking to your friend, but I do suggest that you take a closer look at your relationship with your husband. While you are back together, are there non-verbal clues that you are sending to your husband that don't care for him as you once did? For example, have you ever walked into a room and noticed that two people are in love, even though you don't know them and they are not next to each other? What is it that sends the message? "He brought me to the banqueting house, and his banner over me was love" (Song of Solomon 2:4). The young woman in this poem knew that her fiance was in love with her and that everyone else knew it as well. It could be the way he seeks out eye contact with her across the room. Or, the way he brightens when she looks his way. Or, the small considerations toward her need which tells everyone that she is important to him. While this is talking about the man toward the woman, it equally applies to a woman toward her man. Love is displaying in so many small but important ways. Do you have favorite names for each other? Do you mention small things from your past, indicating that those memories are cherished?
One of my wife's favorite gifts from me is a small ornament -- one of those crystal globes you can shake and see "snow" falling. It contains two bears cuddling. When you wind it up, it plays "You are My Sunshine." It wouldn't seem much to most, but to my wife and I it contains memories. We met in the winter. While we dated, we would tease that "You are My Sunshine" was our song (it was the "in" thing for couples to have a song). After we were married, my wife always tells me she likes to cuddle up with me (she's cold natured). It is not the gift or the cost of the object. It is the memories that it invokes. The fact that I remember tells her more than words can that those memories and she are important to me.
There is a book that I would like to recommend. It is written from a woman's point of view, so it should make a bigger impact than I on this subject. Try finding a copy of The Proper Care and Feeding of Husbands by Dr. Laura Schlessinger. It won't directly solve the problem, but it should give you ideas about how to strengthen your marriage. Before long, the side issues, such as your friendship, will fade away because it will no longer be important.