God's ways are not our ways. What we think is wise is not what God thinks is wise. When Jesus foretells that the disciples will grieve, but that their grief will become joy, He foretells His death and resurrection. At the foot of the Cross (or scattered through the city) and at the death of Jesus, the disciples wept, grieving the death of the Messiah, the one they thought would set Israel free from her enemies all the days of their lives! However, Jesus consoles them saying "your grief will become joy" for He knows already that He will be raised from the dead. God's ways are not our ways because the Lord Jesus knows the full reality of the world and its destiny.
Prudence is a virtue that is often misunderstood. We think of the woman who scrupulously watches over her money or the man who selfishly tends to his own needs are taken care of before he looks to the benefit of others. But this is not prudence: the prudent person is the person who acts in accordance with reality. He responds rationally to the concrete situation he is actually in. We can see this in Saint Paul. The Jews were obstinate in rejecting the Gospel, so "he shook out his garments and said to them, 'Your blood be on your heads! I am clear of responsibility. From now on I will go to the Gentiles.'" St. Paul sees reality as it is. The Jews will not convert, so he moves on. This is an act of wisdom on his part: being able to discern when to stay and preach and when to move on. This isn't always clear! It takes careful prayer and thinking. It requires discovering what the real situation is-knowing reality.
The Gift of counsel
In Baptism and especially in Confirmation, we are given a gift of the Holy Spirit: the gift of counsel in order to assist us in making prudent decisions in conformity of the reality of our situations. This gift is a particular disposition in our souls which make us apt to receiving the inspiration of the Holy Spirit who will guide us in making the prudent decisions because we limited human beings struggle to know the world as it actually is. We quickly make rash judgments about our neighbors (which are sinful!) and are ignorant of many circumstances that have bearing on our decisions. However, the Holy Spirit can really guide us by the gift of counsel.
In a similar way, Jesus counseled the disciples today to help them understand the reality of the mystery of the Cross. His suffering and death seemed to be the end of Israel's hope for the coming of God's kingdom according to our limited way of knowing. However, in reality, the Cross is a great cause of joy for us! By the shedding of the blood of the Lord, our sins were wiped away and the Lord has created new, pure hearts for us.
Our daily crosses pose the same challenge to us. When our projects at work fail, or supper didn't turn out the way we thought it should, or our children are rude and noisy, we quickly find reason for grieving. We complain, get angry, and loose the peace of our souls. I recommend praying for the gift of counsel in order that you might gain a glimpse of the divine perspective that our suffering has real redemptive value. Contrary to our wisdom suffering has meaning and purpose and works for the good of those who love God. True prudence accepts this suffering because it unites one to the Cross. Our grief becomes our joy.