Do I have to...?

I recently had a conversation with an old friend about sharing your “testimony”, basically one’s personal story of how Jesus changes your life. After some discussion, he asked me, “When I give my testimony, do I have to talk about all that stuff about the cross?” What else would we have to share, I wonder? It dawned on me how little we (including me) share Jesus when and if we tell people our stories. Could someone know the good news by the time we’re finished? I’ve learned recently that typically our words and testimonies subtlety challenge people to be moral or religious, but not Christian.