The seventeenth century was a period of political and religious turmoil in the Commonwealth of Poland and Lithuania. The confessional conflicts produced martyrs whose cults consolidated the confessional boundaries of the Roman Catholic, the Orthodox, and the Greek Catholic Church. In my article, I compare three such saints: Josafat Kuntsevych (1580-1623, Greek Catholic), Afanasiy Filippovych (c. 1595–1648, Orthodox), and Andrzej Bobola (1591-1657, Roman Catholic), who were martyred in the hands of their Christian neighbours. For material, I use the hymnographical services composed for the saints. I argue that, in quest of genuine ecumenism, certain content in these services, such as exclusive concepts of the true faith and church unity, may actually induce rather than prevent hostility between the Churches.