In story of Ajamil, I found out that chanting the name of god destroys the sins. He said “Narayana” when he was dying. In Stayarth Prakash , it is written that “Om” is the best name of god. But it does not represent anyone. Like Krishna, Narayana, names etc represent Vishnu. So my doubt is how is “Om” best name and whom does it represent?