Whenever you are arrested and brought to trial, do not worry beforehand about what to say. Just say whatever is given you at the time, for it is not you speaking, but the Holy Spirit. (Mark 13:11 NIV) Be led by the Spirit. Whether you are literally on trial for Christ or, more likely, on trial day to day before man, let the Spirit led you in your words. There is no reason to be anxious about what you will say, that is why the Spirit lives in us, to lead us and guide us. He will speak if you let him do it. If you try from yourself, you will likely stumble over your words. Work can't be done in their hearts without him anyway. It's pretty foolish of us to think that what we say from ourselves matters. I want to encourage you... If you feel the Spirit leading you to talk to a stranger, a friend, or even a sibling or parent - Then DO IT. The fate of eternity lies before them and you have the answer.