I tend to end up becoming a mentor for people coming out of the atheist closet. Perhaps you can help someone on their journey to reality too. Here are some tips.
1. Be kind and never forceful. This is new to them, and they aren't used to talking about religion with someone who isn't forcing it down their throat. Don't become evangelical. They get that enough from the other side.
2. Whatever they tell you they believe, let them know that's okay. Even if it's not what you believe. It helps them open up if they know they won't be told they're going to burn eternally, just for thinking.
3. Almost all of the people who will come to you for this, present themselves as Christian, and may go to church regularly. You are most likely the only person who knows their secret. Never out someone. That is part of THEIR journey. They probably haven't even told their spouse, or if they've tried to broach the subject with them, the spouse wouldn't talk except to say they are going to church more often, or praying about it.
4. Because spouses and family may react that way, you will frequently see these people go back into the closet. They will decide to just deal with it and keep it a secret to save their family. Eventually, most will come to you again at some point because you've offered yourself as someone to vent to. Just keep being that person.
5. Only provide info on why YOU are a non-believer. Never try to say why THEY should be. Offer only the info they ask for, or what is needed to clarify why you believe a certain way.
6. If they seem close to being ready to tell people, offer them these potential scenarios: They can prepare themselves for the barrage of attacks and questions by educating themselves before saying anything; OR they can tell everyone that they don't believe, and deflect attacks by saying they won't talk further about it because they don't want a fight, but that they've made their decision and it's the family's choice to accept it or not. The first one works better for people who are more introverted. The second one is best in my opinion though, because it lets them finally get all of this off their chest. It's a huge burden carrying around that secret.
7. You may have angry family or spouses confront you. Always smile and be extra friendly. Let them see you doing nice things. They are usually working with the misconception that no God means no morals, or reason to be kind. Let them know you aren't trying to convert anyone. You just offered an ear for a friend to vent to, and answered any questions they had. You aren't trying to destroy families. On the contrary; you want people to learn complete acceptance of others, despite different beliefs.
8. Always teach with humor to both your protege and their families. Mention the silliest Bible verses you know; ones that you know almost anyone would think are ridiculous too. Use those as your main reason for not believing, and chuckle at how silly they are. Maybe they will eventually see the silliness of the rest of it.
Finally, you must be open about your beliefs, so that more people can see that it's normal. That normal contributing members of society can be non-believers. Try to be kind, generous, and compassionate, so the world will become more accepting of us, and their struggling family members.
