If you've got "Jesus" on your t-shirt, does it mean you are a Christian?

Yesterday a young woman with a baby asleep in a push-chair and another small child under her arm was trying to get off the bus.  There were several young women near her but none of them helped her.  I wondered why not - it seemed so obvious that somebody should.  When the door closed one very strong-looking, healthy girl turned around, and her t-shirt said "Worship Jesus".  Perhaps that's enough to get you into heaven?  No Christian actions required.