Even if they laugh keep telling them about Jesus, about God's goodness, about God's love. Even if they laugh tell your stories of God's faithfulness, how He pulled you through.
For there will be someone really listening in the crowd. Someone's heart will change. You might not see it. You might not know who or what happened ever. But God will use your courage, your words, your desire to share Him with others. Do it. Don't let the mockers and the ones who are full of themselves stop you from doing what you know you need to do.