To argue in good faith, with conviction, but also with respect - this is a gift that we as Christians can offer the world right now, when we're so divided and at one another's throats. Remember that you are one in 700 trillion, chosen very particularly by God, and so when you run into one of those differences that seem so threatening and insurmountable, remember that God is with you. Create the space for Him to act. Listen, and affirm what you can.