A priestly vocation is a mystery of divine election:
"You did not choose me, but I chose you and appointed you that you should go and bear fruit and that your fruit should abide" (Jn 15:16).
"And one does not take the honor upon himself, but he is called by God, just as Aaron was" (Heb 5:4).
"Before I formed you in the womb I knew you, and before you were born I consecrated you; I appointed a prophet to the nations" (Jer 1:5).
Pope John Paul II - Gift and Mystery
Links:
Daily Readings and Psalms
Everyone can pray for vocations! Here's how.
Experience Lectio Divina
Lectio Divina Web Link
Liturgy of the Hours