Isaiah 35

If you are not totally sold out to the cause or idea, more likely you give up at the onset of challenges. 

That's why you don't buy the idea or cause, you stake your trust on "Who is the Originator" of the cause. If the originator betrayed you, will you trust anymore? I bet you will not.

As for Isaiah 35, the Originator of the 'salvation' cause is God. He will do all that He said He would. And no matter what the circumstance maybe, there's an assurance that He would fulfill His Word. He is definitely NOT like just any man. HE is GOD and NO ONE can change the purposes of His heart.