Norm and Joanne Kettner have developed their own model for spirituality as they age: They give 50 percent of their money to the Lutheran Church and other charities and match it with a significant portion of their free time.

While that type of commitment may seem radical to those who view retirement as a time to focus on themselves and their own interests, the Kettners say that's just the point — serving and giving to the church is their interest, and they want to take advantage of the time they have left in life to do so.

Though their devotion may be atypical, their quest for continued — and even deepened — spirituality as they age is not. With the baby boomer generation now moving toward retirement, and ever-increasing life spans, spirituality has come to the fore as one of the core issues for many older Americans in general, according to aging advocates.

Vaughn Call, chairman of the sociology department at Brigham Young University, said there is some evidence that people attend church more frequently as they age. He helped run a national survey of 13,000 people from across the United States that showed the average number of times people attended church per year. At age 40, the average was 28 times annually. By age 70, the average was 49 times per year, or nearly once a week. After 70, reported attendance drops off rapidly, likely for health and mobility reasons, he said.

Even so, Call said the numbers have to be viewed cautiously, because self-reporting of religious behavior is somewhat suspect. Also, about one-quarter of the respondents were Catholic, one of many faiths that offer several worship services per week, rather than one on Sunday.

If the Kettners were part of the sample, they may well have reported high attendance numbers because they're actively involved in their church. They developed the habit of serving and giving over a lifetime, starting with 10 percent of their income when they were newly married and boosting it by half a percent each year. Married for more than 50 years, they were able to keep the commitment and now encourage others to give and to serve in whatever ways they are able.

Though it has meant living with older automobiles and furniture, they say they would never do it differently. They plan to continue giving and serving as long as they're able. "It all ties together: 'time, talent and treasure' in our church," Norm Kettner said. "I think it's made my faith stronger," adds Joanne. "I think giving and faith go together. It's one way we show our commitment to Christ."