Making the decision to ask to be accepted as a seminarian is kind of like getting up the courage asking someone out on a date. The Church accepts the candidate (the girl says "yes"), and we spend years in the seminary (in my case six years) deciding if this life is for us (in other words, deciding if this girl is "the one").
Here the smartalecks amongst you are dying to challenge me, saying the seminarian is, so to speak, "living with his girlfriend". This is not the case. While at the seminary, the seminarian is not pretending to be something he's not. He's not acting like he's ordained when he knows he's not. Every day I went to Mass and sat in the pews as a layman; I didn't presume to walk into the sacristy and put on Mass vestments, saying that I've already made enough of a commitment and that I plan on getting ordained eventually, so I might as well get used to saying Mass. Cohabitation is when a couple acts like their married even when they know they aren't. But I digressed a bit.All the while, we can decide this isn't for us and walk away, and hopefully remain "friends". I've got more than a few friends who were seminarians with me who made such a decision and are very content living their Catholic faith as lay persons.
But if we persevere (and both the dater -the seminarian- and the datee -the Church- consent) and the relationship continues, then it's time to take it to the next level. That's our ordination to Diaconate. In my analogy, that would be akin to the proposal of marriage, the giving of the ring, etc. After that, everything points to ordination in a more urgent sense. Invitations are sent out. A party is planned.
Ordination to the Priesthood is the wedding day. Though I didn't literally say, "I promise to be true to you in good times and in bad, in sickness and in health. I will love you and honor you all the days of my life", to a physical bride, I conveyed those same feelings to my supernatural bride (the Church) in answering "I am" to the questions asked to me by my Bishop: Will I care for my bride (God's flock) as a conscientious co-worker of the bishops?; Will I celebrate the mysteries of Christ religiously and faithfully as they have been handed down by the Church for the glory of God and the sanctification of my bride?; Will I preach the Gospel and teach my bride worthily and wisely?; Will I consecrate my life to God for the salvation of my bride? Though I hadn't met them yet, I said it to my future parishioners: not only the ones I've already met in my nine years of Priestly service, but the ones I still have yet to meet.
A Priest's "first Mass"? That, my friends, brings us back to my original point: It's the wedding night. It's what he's been waiting years to do with anticipation. It's when he gets to say "This is my body, given for you" to his spouse, the Church. He's spent more than a few hours worried about his "performance", and he's probably asked for some advice from more than a few "bridegrooms" who've gone through the wedding-night jitters years before. The only difference is that a Priest's wedding night is done in the presence of his family and friends. Talk about "performance anxiety"!!! Any married couples out there had their parents watching their wedding night from front-row seats, and with a photographer and videographer looming about???
And that brings me to where I am today, nine years later. After the wedding day, the reception, and even the honeymoon, comes the tough part: actually living the vocation day-in and day-out. The same dangers are there for Priests as for married couples: We can stop communicating with our spouse (lack of prayer). We can complain we don't have enough "me-time". We can become strangers to each other. We can sometimes find our spouse asks us for things we don't necessarily want to do. And, yes, even the nuptuals can creep into routine. In either vocations, Holy Orders or Matrimony, it takes work and deliberate will to keep it new. Those can only be fed by love. Not a fleeting lust that goes away when the bride & bridegroom aren't skinny & beautiful anymore. But a deep love, like a bank account, that continually gets deposited into so that it can be withdrawn from when the need presents itself, all the while growing while gaining interest.
OK, enough rambling. Go back to your lives.