Serving God sounds like such a peaceful job. For Bishop Richard Lennon, it’s been anything but. He spent seven months as interim leader of the Archdiocese of Boston during the thick of the Catholic priest scandal, only to come here to face a different sort of crisis: a decline in the number of Catholics in the diocese (about 185,000 less than 30 years ago), coupled with an exodus of parishioners from the city to the suburbs. Lennon’s reaction was quick, decisive — and controversial. Called Vibrant Parish Life, the plan created 69 clusters into which the 230 parishes were grouped. He then announced that roughly one-third of the clusters would be asked to consolidate and close parishes. “It’s using all our resources in as wise and prudent a manner as possible ... to carry out the mission of the Lord,” Lennon said in theCatholic Universe Bulletin.