At what point in your spiritual journey should you start sharing your faith with others? When is full disclosure about your relationship with Christ appropriate to tell others? The answer is really simple: RIGHT NOW!!
Instead of waiting to mature, simply share what you know right now. What has God done for you? How do you know God is at work? What difference has God made in your life? These are questions that others are looking for answers to and you don't have to a Christian for a long time to answer these questions. Simply share what you know!!
