The author is looking for an answer to a pivotal question: what is upbringing in faith and not how to bring children up in faith. This task seems to be especially difficult due to lack of professional research in the field, both in Polish and foreign literature. On the other hand this fact obliges researchers to get down to this topic. Another diffi culty is that faith is complex phenomenon. On the one hand it is God’s gift and on the other a totally free human act. Although it is a grace the act of faith manifests itself taking into account all human factors, for such is the law of the incarnation and faith is always „incarnated” into all human. Moreover faith may by analysed in various dimensions. All this makes the process of upbringing in faith extremely complex. In his paper the author focuses on chosen apects of the problem. The first part refers to terminological ambiguities related to the analysed topic. Afterwards the author turns to a catechesis in service of faith. The third part is refl\exion on a relations between faith and upbringing.