Feast of Cyril & Methodius, Missionaries to the Slavs, 869 & 885 Commemoration of Valentine, Martyr at Rome, c.269 The offertory is the first essential action of the Liturgy, because in it we make the costly and solemn oblation, under tokens, of our very selves and all our substance, that they may be transformed, quickened, and devoted to the interests of God.