TWO PEOPLE we will call Tom and Stacey do something with their seven-year-old son, Lindsay, that 1960s prophets predicted would become a folk memory by the 1990s. They take him to church with them on Sundays. This professional couple crowd their way into Trinity Church in Aurora, Ont., one of the commuter towns on the perimeter of Canada's new Toronto megacity. They are not unusual, the church being filled with other "905ers" as people in this populous semi-circle are called because of their telephone code. Nor is Trinity unusual. Although Canada's mainline denominations have been on a statistical slide for more than 30 years, there is an increasing number of growing churches from the …