She lied to Lin because she was right. It's the Avatar's duty to maintain order and to take on the biggest objectives. Had she listened to Lin and Korra went back to Republic City. Zaheer would have won, and would have never been stopped.
We don't know what happens yet. We'll have to wait until Friday.
true
Korra keeps on talking L's Zaheer fukked her over mentally



didn't watch the episode yet no spoilers 



face until i saw her hair had changed