I think the narratives we hear over and over have created a misconception that many migrants are encouraged to leave their their homes and circumstances to go to the United States. This scene showed me something different. Rather than a rousing, motivational speech, the priest really wanted those attempting the journey to think of their alternatives.
I wonder if it is possible that many migrants aren't actually aware of the multitude of dangers they will face. How regularly do they hear from friends and family who have gone before them? Even though they were living in the same small country, Soledad and Rebecca rarely heard from their own father. They didn't necessarily know of the horrible dangers of the city where he was working. How many have cell phones to touch base with one another en route? I wonder if family members would even be truthful. For example, had Soledad and Rebecca been able to talk with their father, I don't think they would have told him about the kidnapping, jumping on and off the trains, or the physical attacks. Is there access to news stories via TV or newspaper? Are journalists along the route publishing stories about the danger, or are they bullied by cartels to suppress this information? I think the priest wanted to be certain they all really, truly understood what they would be up against.
Lydia's situation was completely different from many of the people she met along the way, in that she did have, at one point, a secure, middle class life. Maybe it is easier to leave if you have very little or nothing to begin with. How could it possibly get worse, right?