30. Without doubt, all these principles of Christianity, which the Virgin Mother of God incites us to follow with eagerness and with energy, can be entirely and lastingly productive only when actually put into practice. Taking this into consideration, We invite each and every one of you, Venerable Brethren, by reason of the office that you exercise, to exhort the clergy and people committed to you to celebrate the Marian Year which We proclaim to be held the whole world over from the month of December next until the same month of the coming year - just a century having elapsed since the Virgin Mother of God, amid the applause of the entire Christian people shone with a new gem, when, as We have said, Our predecessor of immortal memory, Pius IX, solemnly decreed and defined that she was absolutely free from all stain of original sin. And we confidently trust that this Marian celebration may bring forth those most desired and salutary fruits which all of us long for.