Spritual Emptiness can only be found by any induvidual when he starts accepting his/her mistake. When he logically reasons with his actions, speach and toughts. This is what is said is every religion be it Hinduism, Islam, Budhisim, Sikhism, Jainism, etc.
Most of think that one is superior over other, the real fact is that God just gave different religion to test our compassion to others. If we realize that then that is enough and there ends the suffering and Humans have always had a heart with a hole that never gets filled, we should be happy at what we have right now and enjoy the day as if there is not going to be a day like today. Rather we have the tendency of planning on whom should it fight with tomorrow or how much should I earn for the month, etc.