You want your friends to respect God. It angered you that they used his name in vain, blasphemy, etc., right? Before you can save these friends from hell or defend your faith, you must be able to discuss God freely without anger and gain their respect. To gain respect, you need to give it, display it and earn it. It is commendable that you have a vast knowledge and can support your beliefs. The goal you have however, isn't to win the conversation, stump them or have the right answer. You want their respect. Not a wall to protect themselves from you. Christians can say shut it and not go to hell, (Elisha called bears to attack boys teasing him). Don't kick yourself on that one, or do it really quick and walk on before you get lame. Don't assume the men above hate God or will go to hell for their blasphemy, either. It doesn't make it ok, and it doesn't make it something you have to hear. Responding in anger and preaching won't gain the respect you need. Take what they know of you and put yourself on the other side. Look at the interaction from their point of view. You are 13, they are 20, 30, 50? Lets say a four year old interupted the chat and started preaching to you about God and life. Ripped you apart for telling this man to shut it. You have experiences a four year old can't imagine, let alone comprehend. You know that no matter how hard you try, you will make mistakes. Sometimes they turn out good, Thank God! A four year can't relate to your mistake and remorse. These men can. Respect that they have lived longer, have experiences you don't know or understand, and feel anger. (not much different then yours) They know that no matter how hard they try, life isn't fair. Sometimes the best reprimand is not giving one. They won't go to hell for calling God a bad name. (Who did that to Jesus on the day of his cruxification?.) Respecting them shows you have the ability to respect God. If they are using this to gain your attention and get you mad the best thing to do is not give them any for it and definitely don't get mad. If this doesn't work or this situation escalates, you may need to remove yourself from it for awhile. Return when you are ready. Relax, pray for them, you and the situation. Giv up? hell no! switch tactics and let God win the battle. The Devil wants you to think these guys are going to hell for swearing. He feeds on that fear/anger and it helps him keep them from God and you. (the wall they're building in defense)