When you feel the urge to share your faith but you don't, God holds you acccountable. If you share the best you can but the person won't pay attention to you, you still have done your part. Don't be discouraged, God has given you an important job, but you are only responsible for doing that job. You aren't responsible for the results. Share God's love and God's grace with a gentle, loving spirit and trust God to do the rest.