Children's religious education is traditionally oriented to initiate children into a religious tradition. The idea--that the child must first receive input and then, when growing up, can start thinking critically--is based on images of children as "not-yet-adults" who should be socialised and protected. Here I will develop an ethical reflection on images of children. From a Christian viewpoint, children should be seen as "persons". Children are competent subjects, with their own religious ideas. I defend the relevance of children's participation: they are seen as having a voice, actively contributing and being part of a practice in families, schools and society in general. I will focus especially on families and show how the idea of "participation" as a model for religious education not only means children's "initiation" into a religious tradition, but also taking seriously children's own insights. Based on the ethical reflection upon the image of the child as an active subject and the relevance of participation, I will show that the Louvain hermeneutical-communicative model of religious education is relevant for education in families with young children. This model integrates heteronymous input and critical thinking.