BERLIN, July 20 (Xinhua) -- Catholic and Protestant churches have lost a combined 660,000 members in 2017, the two churches announced on Friday. Now, only slightly over half of the German population belongs to one of the two Christian denominations.

According to the Evangelical church in Germany (EKD) the number of Protestants fell by 390,000 members to 21.5 million in 2017, a decrease of 1.8 percent. The German Bishops' Conference (DBK) released their numbers which show 270,000 Catholics had left the church which currently has 23.3 million members in Germany.

Overall, 54 percent of the German population still belongs to one of the two Christian churches. In 2005, the figure was still at 62 percent.

One reason for the decreasing member numbers is the aging population in Germany. In 2017, 350,000 members of the Protestant Church died, compared to 240,000 of Catholics. Young Germans are less likely to become a member in the first place.

The demographic change, however, cannot be the only reason for the continuous decrease of members, Andreas Puettmann, the author of "Society Without God" argues. "The decline in membership is less demographic than due to the fact that making faith a tradition in families, communities and schools does not work properly," the church expert told the German press agency (dpa).

Sociologists specialized in religion, reason it may be less the fault of the churches and what they offer. General social developments, such as increasing prosperity, individualization, urbanization, diverse leisure opportunities, expansion of education and increase in mobility, all these things make it less necessary especially for young people to be part of a church.

According to Puettmann "only one in three says they are interested in religious topics."