Two examples:
1) In Idlib, the Syrian army was beating the FSA so the FSA cried and called for a ceasefire. They used the ceasefire to regroup and bring new fighters from other parts of Syria. They then violated the ceasefire. This had the effect of stopping the momentum of the Syrian army. I don't know why they agreed to a ceasefire in the first place when they were clearly winning.
2) After the battle between the FSA and the YPG, a local Kurdish group, at least 18 FSA members were killed. Some of them were also injured. A woman Kurdish commander agreed to meet the leaders of the FSA to give them back their dead and injured and have an exchange. But the FSA lied. When she was in their custody they executed her. The execution angered the Kurdish people, drawing 20, 000 protesters to the streets. I don't why the Kurdish commander agreed to meet with the FSA. It was a stupid decision. You can't trust them. Their word is backed by nothing.
The FSA can't defeat their enemy on the battlefield. They use deceit to inflict damage, exactly like the Mossad.
It is clear the FSA cannot win a major battle fair and square. They use deception, executions, and terrorism. These are the weapons of the weak. They will be defeated in Syria.