I've watched all 4 seasons of the show and even though I love it, I guess I just don't get science fiction. What I don't understand is this: The people of the future abducted the 4400 and sent them back to earth with special abilities that were supposed to save mankind. Then, the people of the future wanted Isabelle to kill off every 4400 and the "marked" also wanted to eliminate the 4400. Why did they give these people these powers and then tried to kill them all. This makes no sense to me. What am I missing here? Thanks to all who will respond.

The people who abducted the 4400 and gave them abilities aren't the same people that created Isabelle and want to eliminate all the 4400. There are two factions from the future. Borg lady's faction(Maia's fake sister) and the Marked.