Here are some tips that might guide you:

Nature/Plants = GOD

Who are humankind really fighting? Terrorists, governments?

Or maybe ourselves. Are we winning? Well, are we living our lives as we were supposed to? Are we good Christians.

The religious reference in The Happening, is the same as we saw in Signs.

In the happening, the message is that we should live happiliy in harmony with ourselves and our environment; get married, take care of each other, laugh, have babies.

Do not be mislead to think that we have any other enemies than ourselves. If nature punishes you, it was mankind who threw the first punch.

The proof of this underlying plot of Christian belief:

Do you remember when the attack in the film started....?

Well, it was 8:32.

Do you remember when it ended?

It was 9:27.

Google "8:32" or "9:27" and your top hit is a reference from the bible. A message from GOD. Delivered from the profet M. Night Shyamalan.