Last year only 544 men were ordained as Catholic priests to serve 67 million Catholics, a quarter of America?s population.

By contrast, some Protestant seminaries graduate over 1,000.

The major reason so few choose the priesthood is celibacy, the rule that a priest may not marry. A man must choose ?God or the girl.?

What is that discernment process like?

A thoughtful three-part series on the A&E Network profiled the emotionally wrenching choice by four young men, the most important decision of their lives.

Two hours were broadcast on Easter Sunday, two more on Monday. Joe Adair, 28, has been in a quandary for a decade.

A campus counsellor at John Carroll University, he?s been in and out of the seminary twice, and considers re-entering.

Why? ?I feel forced by my parents to be a priest. I realise that it is not the right motivation,? he confesses.

Dan DeMatte, 21, has a deep passion to serve the church. He leads a high school youth group, and lives with nine other celibate young men at Ohio Dominican University, but is young and not sure he is cut out for the priesthood.

Steve Horvath, 25, stunned his family and friends when he gave up a promising career as a high paid consultant with a $500,000 condominium to be a campus missionary who has to beg for financial support.

?It hit me that I might be called to be a priest. Most people would not understand.? And he?s uncertain himself.

Mike Lechniak, 24, grew up admiring his parish priest, Fr. Paulselli. But he?s also fallen in love with Aly, who longs to marry him. He has trained as an elementary school teacher, and was offered a job when he debated giving up the girl and teaching to become a priest.

?The greatest sacrifice would be the loss of a female companion for the rest of my life,? he acknowledges. ?Aly would be heart-broken.? In the weeks that the young men debated whether to enter (or re-enter) the seminary, each took on a service project to help them sort through their emotions.

Joe decides to go to World Youth Day in Germany which would also give him a chance to see Anna, a German girl he met in the US. Thus he can consider God or the girl. He stands on a sidewalk, where the new Pope Benedict will pass by. Sure enough, the Popemobile drives by slowly and Benedict seemed to look directly at Joe and smile, which he thought significant.

World Youth Day actually lasts several days.

However, not until the second day from a vast field of hundreds of thousands, does Joe call Anna. Afterward, he confesses, ?Anna was upset that I have been here two days and had not called her. I have never experienced her being so angry. It did not go well.?

Dan leads a group of high school students to to kneel outside of an abortion clinic, to pray for the women entering there and for their unborn babies. Two women in their 20?s ask, ?What are you doing?? ?We are praying for victims of abortion,? Dan replies. ?Why shouldn?t women have the choice to have an abortion,? a woman asks.

?We do not believe a woman has a choice to kill somebody.? The confrontation thrills him, but he still asks himself, ?Should you dedicate your entire life to building up the body of Christ?? His priest encouraged him to carry an 80 pound cross for a 22 mile hike. After four miles he is in intense pain. He falls frequently but friends walking with him help him. ?In carrying the cross, I had to trust God would guide me,? he sighs.

Steve left a prominent consulting firm, to consider becoming a priest. However, he has shared his thinking with almost no one. Therefore he decided to go to his alma mater, the University of Virginia, to talk with former fraternity brothers about his career choice.

?Can you date if you are a seminarian?? asked one brother.

?Yes, you are able to date at that point, but it would be as if you are engaged and were seeing other girls,? Steve replied.

His fraternity brothers were surprised, but hugged him and wished him well. ?They hit a home run today, and totally backed me up,? he exults.

Mike?s mentor, Father Pauselli, suggests that he make a retreat to consider his choice between priesthood or marrying Aly.

He confesses, ?I wanted to jump in my car and go see her. I miss everything about her.? What will they decide? Tune in for the final show at 11 p.m. tomorrow.