The change in velocity (delta-v) of a rocket is equal to the exhaust velocity of the propellant times the natural logarithm of the total initial mass of the rocket divided by its final mass after the propellant has been expelled. This is called the ideal rocket equation. This is rocket science. I like rocket science. And parish based evangelization is not rocket science.

Parish based evangelization is the heart of Disciples in Mission. Indeed, the whole reason for doing something bold and creative like Disciples in Mission is that we know that parish based evangelization works. We can train for it. But we need strong parishes in order to do so.

Ultimately, the New Evangelization is not a set of strategies, not a set of bullet points which, if we can check them all off, we've "accomplished" the task. The New Evangelization is about one-on-one encounters, with people who are formed and trained in the art of witnessing to their faith, inviting their fellow Catholics back into a powerful and transforming love relationship with Jesus.

Nevertheless, there are simple things that we can do, and some best practices that we can follow.

In the Archdiocese of Boston, on any given weekend, about 250,000 people attend Mass. Let's assume that 80 percent of them carry cell phones -- that's 200,000. A Pew Research Center study in May of 2013 determined that 40 percent of cell phone users use those phones to access social media sites, like Facebook. So, each weekend, some 80,000 people attending Mass in the Archdiocese are able to post on Facebook from their cell phones. Now, how many "friends" a Facebook user has is strongly dependent on their age. I'm 50, and in my age group the average number of friends is 183. For someone age 18-24, the average number is 510. Let's use 200 as our overall average, which is conservative. If all of the 80,000 people who both go to Mass and can access Facebook from their cell phones were to "check in" when they get to Mass, what would happen? Sixteen million times, people would see "I'm at Mass at ..." Every weekend. That sort of simple action can begin to change the prevailing concept that "no one goes to Mass anymore." And, the change would be most strongly felt among the very population that we need most strongly to evangelize. And ... perhaps most importantly of all, the person who has made the post now begins to adopt the identity of an evangelizer.

The New Evangelization is not a parlor trick, or some clever strategy that keeps us from needing to really witness, face to face. But, we have tools that are becoming broadly available to us at the very moment when we are being broadly called to engage in evangelization. I do not think we should ignore the significance of this.

There are other simple things as well. When you invite someone to your home, you don't wait for them to find a seat -- let them wander around the house, and perhaps sit by themselves in an empty room. You invite them to come sit next to you. How about this: Next time you're at Mass, and you see someone you don't know coming up the aisle, move over and invite them to come and sit next to you. And what if most people in your parish were doing this? How would that change the way your parish looks and feels to someone who is just starting to try to find their way back?

From time to time in these articles I will issue challenges to the readers of The Pilot. Today I have two. First, if you have a smart phone and you are able to use it to access Facebook, next time you're at Mass, check in. Second, next time you see someone coming up the aisle whom you don't know, move over and invite them to come and sit with you.

It's not rocket science.

Father Paul Soper is Director of Pastoral Planning for the Archdiocese of Boston.