Almost every act in nature can be seen to bear the cross.  A plant grows up, overcoming its' cross of gravity.  A raindrop falls into the sea and is malformed by the friction of the wind, its' cross.  Everywhere there is friction somewhere.  The only religion to give us this natural sign of struggle and and difficulties is the Catholic one.  Buddha comes on elephants and with fanfare.  Jesus comes to us bearing the sign of even a natural struggle, made supernatural.  The Cross is unbeatable.