One of the problems resulting directly from the definition of liturgy is the relation between cult and sanctification. It is connected with the double subject of liturgy, that is Christ who is present in it, and the believers who participate in it. In Christ’s activity in liturgy priority of the cultic dimension may be seen, from which sanctification of man follows. Hence in this case cult is the supreme and superior category. This priority follows from the nature of Christ as the Son of God. It is the other way round in the case of man, who, before adopting the cultic attitude has to be sanctified first. So for him cult is the purpose of liturgy that is achieved by his earlier sanctification. This thesis is confirmed by the two definitions of liturgy contained in the encyclical Mediator Dei and in the Constitution on the Sacred Liturgy Sacrosanctum Concilium of the Second Vatican Council. The entirety of these documents allows noticing continuity in defining liturgy that has the cult of Christ as its main purpose, the Church joining the cult, and in the Church the believers doing the same, via sanctification.