Earth is invaded by Aliens, but it turns out that they're peaceful and happy and so everyone loves them.
Obviously humanity has tons of questions they'd like to ask so a conference is arranged. World leaders, public intellectuals and religious heads are invited to ask their most important questions.
It is the Pope's turn to ask a question;
Pope: "I was wondering...have you ever heard of our lord and savior Jesus Christ?"
Alien: "Jesus? Yes of course! He stops by our planet every couple of years and we all have a big party"
[The Pope looks confused]
Pope: "You must be mistaken...Jesus Christ was here about two thousand years ago but he left and we've been waiting for his return ever since...why would he visit you so often?"
Alien: "Well..."; they look at each other "...maybe your chocolate wasn't good"
Pope: "Pardon me?"
Alien: "When Jesus first showed up on our planet we gave him really great chocolate...what did you guys do?"