Yes, I think Divergent is appropriate for teens to watch.
Here's the plot summary:
"Set in a futuristic dystopia where society is divided into five factions that each represent a different virtue, teenagers have to decide if they want to stay in their faction or switch to another - for the rest of their lives. Tris Prior makes a choice that surprises everyone. Then Tris and her fellow faction-members have to live through a highly competitive initiation process to live out the choice they have made. They must undergo extreme physical and intense psychological tests, that transform them all. But Tris has a secret that she is Divergent, which means she doesn't fit into any one group. If anyone knew, it would mean a certain death. As she discovers a growing conflict that threatens to unravel her seemingly perfect society, this secret might help her save the people she loves... Or it might destroy her."
So again. Yes this movie is ok for teens to watch.