Recently some Reformed denominations have embarked on church planting in the major cities in the Netherlands. This was done mainly for evangelistic reasons. From a quantitative perspective this project has been rather successful. However, many of the new churches deviate in some respects from official doctrines and practices of their denominations, as a consequence of contextualization. This has provoked some protest, leading to the failure in at least one case of instituting a new church plant as a full member of one of these Reformed denominations. In this article we add research data to this experience, demonstrating that this is not an isolated discussion. Moreover, we use this experience as a point of departure for an ecclesiological discussion about the continuous reformation of the church. The conclusion is that church planting is an occasion for ecclesial reconstruction with a view to mission, and we make some suggestions how this should happen. Recently some Reformed denominations have embarked on church planting in the major cities in the Netherlands. This was done mainly for evangelistic reasons. From a quantitative perspective this project has been rather successful. However, many of the new churches deviate in some respects from official doctrines and practices of their denominations, as a consequence of contextualization. This has provoked some protest, leading to the failure in at least one case of instituting a new church plant as a full member of one of these Reformed denominations. In this article we add research data to this experience, demonstrating that this is not an isolated discussion. Moreover, we use this experience as a point of departure for an ecclesiological discussion about the continuous reformation of the church. The conclusion is that church planting is an occasion for ecclesial reconstruction with a view to mission, and we make some suggestions how this should happen.