The Rockland Congregational Church is offering “A Natural Heart,” a one-day Lenten retreat and spa today. It will be from 10 a.m. to 2 p.m. Saturday, March 24, and it will be led by the church’s director of education, Carole Hallundbaek. Those who attend will be invited to relax, calm their minds and connect with the spirit and mystery of Lent. The schedule includes breathing instruction, an introduction to tai chi, readings from Sidney Poitier’s best-seller “The Measure of a Man” and a generous introduction to Taize meditative song with Billy Smith, member of St. Peter’s Episcopal Church, Rockland. The Rockland Congregational Church is at 180 Limerock St.