From the Find Madeleine Website, Home page:
Why do we continue?
There is absolutely nothing to suggest that Madeleine has been harmed.
Madeleine is still missing and someone needs to be looking for her.
She is very young and vulnerable and needs our help.
We love her dearly and miss her beyond words.
The first two reasons given in answer to the question - and therefore presumably the most important - are another example of distancing / projection.
Point 1: This sentence is not about 'we', and is not really an answer to the question
Point 2: Someone needs to be looking for her
The third and fourth are more meaningful / personal, but they do not make it to the top of the list.
Why they do continue ? Continue what actually ?
What if they put an end to "continuing" ?
"Nothing" is wishful thinking and "absolutely" is "insulting people's intelligence" to borrow one of their favourite expressions : Eddie picked it up as soon as the door was open.
The interesting part is "someone needs to be looking for her".
Who is someone ? Either she's alive (and necessarily well) or she's dead. In no case does someone (who?) need to look for her. If she's alive and didn't forget who she is, she'll pop up one day. If she's dead, let the dead bury the dead.