There have been recent rumors that there are approximately 800 congregations in Europe that are considered "too weak" to continue to function and that will need to close in the foreseeable future. The reliability of these numbers, let alone their sources, appears highly questionable. Although I do not have any official information to refute these rumors from reliable sources, I wanted to make some comments regarding LDS congregational growth trends and congregational decline.
First off, I find it hard to believe that there will be anywhere close to 800 units discontinued within Europe within the next two decades, let alone the next couple years as the rumor indicates. There are only 1,302 congregations (808 wards, 494 branches) within the Europe Area at present, and only 194 congregations in the Europe East Area. If this claim applies just to the Europe Area, which services Western Europe and Central Europe, it would mean that 61.4% of LDS congregations in the area would be discontinued (53% if the Europe East Area is also included). Aside from countries that used to have a more widespread LDS presence but no longer do due to political or military issues (e.g. Afghanistan, Iran, Iraq, Vietnam), there has NEVER been as large of a percentage decline in congregations for any country of world region. Provided with the percentage decline in the number of wards and branches from their all-time highs in parentheses, the countries that have experienced the highest percentage declines include Belgium (41%), Panama (37%), and Chile (36%), However, even these countries have experienced these declines over a period usually a decade longer or more, not a mere couple years. Furthermore, all three of these countries, and most countries that have experienced similar significant trends in the decline in the number of congregations, eventually reach a point when consolidations slow until stagnation. Sometimes, trends can reverse or resume given a variety of changes in church policies, receptivity, and other issues.
It is likely that there is a plan to consolidate LDS congregations in Europe. In fact, this has been the trend in most European countries since the early 2000s. However, these unit consolidations are generally carefully considered in order to avoid longer distances to meetinghouses resulting in a reduction in the number of members who attend church services. Furthermore, it is common for unit creations and consolidations to vacillate over time based upon area policies, receptivity, goals for growth, and vision for mission outreach. Eastern Europe is the quintessential example of this phenomenon as the Church in Moscow, St. Petersburg, Yerevan, and Sofia has undergone multiple iterations of congregations closing and later being re-created. Unfortunately, this process results in many members lost in the reshuffle due to problems with socialization, assimilation, and longer distances to meetinghouses that discourage some to stop attending. It has been quite the vicious cycle in some area, especially major cities in Russia, that I believe significantly delayed the creation of stakes in several cities for many years.
Recently we have published the number of active members in many wards and branches in Europe based upon thousands of surveys collected from returned missionaries and local members. This data is accessible on cumorah.com via the LDS International Atlas. The most complete data we have in Europe is for Scandinavia, the British Isles, France, Germany, Italy, and Spain. Like most areas outside of North America, wards in Europe are significantly smaller than in the United States and Canada. Most wards have between 50-150 active members, whereas most branches have between 10-50 active members. There has not been any significant change in the number of active members per congregation for most European countries during the past decade according to reports from returned missionaries and local members.
Lastly, I wanted to emphasize the seriousness of congregations closing and its impact on LDS growth trends. My experience over the years of collecting data and researching LDS growth trends indicates that congregation consolidations often do not result in noticeable improvements with member activity or convert retention rates. The idea sounds good on paper when congregations struggle, especially if it has been for many years, as congregations with more active members may provide greater opportunities for fellowshipping, socialization, and staffing leadership/callings. However, this strategy appears to address the symptom rather than the root issue of the problem for why congregations struggle to grow and maintain self-sufficiency. These challenges should prompt reflection on what needs to change with local members, leadership, and missionary tactics rather than structural and organizational changes that temporarily ward off these challenges. Even small congregations can become productive and serve as important outreach centers to the population they administer after years of stagnant growth or decline. For example, the Church in Indonesia has struggled for years to revamp growth after several decades of essentially extremely slow membership growth and congregational growth. Despite these challenges, the Church has maintained one branch each in Manado, Sulawesi and Medan, Sumatra since 1984 and 1994, respectively. It is quite remarkable that mission and area leadership did not close either of these branches as both have historically had only 20-30 active members, lacked sufficient local leadership to properly operate, and are isolated from the body of church membership and mission headquarters in Java. Despite these long-term challenges, the Church in both the Manado Branch and the Medan Branch has experienced steady growth within the past few years. Today both branches are fully staffed by native branch presidencies. Church attendance has also significantly improved in these units based upon recent reports. These improvements appeared attributed to changes in the way the mission has approached missionary efforts in these cities such as changing the meetinghouse location, the focus of proselytism, and the implementation of more effective teaching and finding tactics. Thus, diligence in maintaining struggling small branches, particularly ones in locations without a nearby LDS congregation, can have high pay-offs for long-term growth if missionary activity becomes more productive and cultural conditions become more favorable for growth. The reestablishment of branches in cities where branches once used to operate can become a much more challenging feat than continuing to maintain struggling congregations.
For more information on effective approaches to proselytism and missionary work, I suggest you listen to the 2014 Dialogue Podcast of a presentation given by me and David Stewart, particularly David Stewart's comments at the end of the presentation.