This article addresses two current debates that have generated increasing interest in a number of countries but have rarely been considered together: the debate on religious and interreligious literacy and the debate on the assessment of the outcomes of Religious Education (RE). Against this background, both debates are reviewed and critically discussed in relation to the following questions: 1) What guiding educational ideas are connected to the new or renewed interest in religion-related knowledge, and which ideas form the shared motives that influence the two debates? 2) What is the empirical basis of these debates? The results indicate that the educational basis of the two debates is currently underdeveloped, and their empirical foundations are rather weak. In addition, there is a need to direct attention towards strengthening religious and interreligious literacy in, for example, RE. The debates on both (inter-)religious literacy and the assessment of the RE outcomes should be based on clear educational guidelines and informed by solid empirical results that directly address religious literacy and the religion-related knowledge of young people. Moreover, we conclude that the two debates should be developed together, as they both require enhanced theoretical understandings and empirical insights.