A discipleship group is a gender-specific, closed group of four to six believers (men with men, women with women) who meet weekly for a predetermined amount of time.
Group size. The best size for a group is four to six individuals. I have had more and less and it worked fine, but the sweet spot seems to be four to six. It is enough to create good discussion and not too many, so everyone gets a chance to be involved.
Age and stage. It works best when the leader is one or two stages of life ahead of the group. When I was a young dad, I led men who were newlyweds. I led guys with young families when I had teenagers in the house. Most people want a mentor who is where they want to be. It also works with being one or two stages ahead spiritually, regardless of age.
Chemistry. Try to know a little about a person before you invite them. The two big categories I don't like to mix are married versus not married and kids versus no kids. Diversity can be very good for a group, but some differences become a distraction from what you are trying to accomplish.
Why same-gender. Men become men in the presence of other men. Men speak a different language. We talk to each other very differently than we speak to women. Men don't like to open up face-to-face as women do. They are naturally guarded. Even the very talkative and outgoing guys usually keep the conversation on a surface level. While it is true that getting men to speak initially is difficult, they will not stop talking once you get past the surface level. I am trying to create a safe place where my group can be transparent.

