This dissertation will argue that the ecclesiology of 9Marks reflects both an appeal to historical Baptist ecclesiology as well as the introduction of new emphases. Three key ecclesiological themes in 9Marks writings are examined, namely: regenerate church membership, congregational polity, and plural elder leadership. The first chapter summarizes the state of contemporary ecclesiology and the definition of key terms used throughout the dissertation.

Chapter 2 considers the background of 9Marks including its history, impact, and importance amidst the broader Baptist landscape. It seeks to articulate the positions of 9Marks concerning membership, polity, and leadership using primary source material from their own corpus.

The third chapter focuses on historical Baptist ecclesiology from the first Baptist church in Holland with its Short Confession of Faith in XX Articles (1609) through the Abstract of Principles (1858). It traces the echoes of the past through confessions, covenants, creeds, catechisms, and key secondary sources in order to articulate a consensual historical Baptist stance on regenerate church membership, congregational church governance, and plural elder leadership.

Chapter 4 evaluates the continuity and discontinuity between 9Marks and historical Baptist ecclesiology. The analysis shows how to a large degree, 9Marks is calling Baptist churches back to their historical roots. However, it also demonstrates that in some areas, 9Marks is emphasizing new norms for Baptists.

The last chapter provides a conclusion to the dissertation—including historical, biblical-theological, and pastoral implications. It provides insights into membership polity and leadership for contemporary church practitioners to evaluate their current ecclesiological positions and pursue healthy church life. Finally, this chapter also describes related subjects that merit future research.