Be honest (i.e. don’t pretend to believe what you don’t believe), don’t be rude, don’t be obnoxious and apart from that don’t think too much about it. There will be both positive and negative consequences of whatever you tell the believers, the extent thereof you could hardly predict. If they want to discuss religion with a skeptic, let them take the responsibility to do so. If they don’t, respect their choice.
Be honest (i.e. don’t pretend to believe what you don’t believe), don’t be rude, don’t be obnoxious and apart from that don’t think too much about it. There will be both positive and negative consequences of whatever you tell the believers, the extent thereof you could hardly predict. If they want to discuss religion with a skeptic, let them take the responsibility to do so. If they don’t, respect their choice.