The fourth phase of the international Lutheran-Roman Catholic dialogue resulted in a final report, The Apostolicity of the Church (AC), which was published in 2006. The convergences described in this document are best understood in light of the earlier stages in the Lutheran-Roman Catholic dialogue, especially in relation to the Joint Declaration on the Doctrine of Justification (JDDJ). AC seems to move beyond the 'differentiated consensus' of the JDDJ as it aims at some form of 'differentiated participation' of Lutheran and Roman Catholic ministers in the same apostolic ministry. A careful study of the way the topic of apostolic succession is dealt with in AC shows that a central aspect of the Roman Catholic concept of apostolic succession remains somewhat invisible in the document. This aspect can be made explicit in terms of the relation between faith and institution. The fact that this issue remains unaddressed may hinder the very attempt to determine the content of the proposed 'differentiated participation'.