It’s not that God will not give you anything you cannot handle. It’s that He will enable you handle that which you cannot handle on your own. 
We are like a little boy who tried to remove a large rock in the middle of the sandbox. He tried his best but he simply didn’t have the strength to remove it. Dejected, he went to his dad and told him his problem. “Daddy, I did everything I could to remove that rock, but it didn’t budge.” But dad answered, “No. You didn’t. You didn’t ask me!” 
When God gave the task of leading the Israelites out of Egypt to Moses, God did not size up Moses and thought that he could do it and therefore the job went to him. No. God knew Moses didn’t have it in him. But God would enable Moses to do that which he cannot do on his own. 
That is the way it works with god-given tasks. If at first you think you can do it, it probably isn’t from God. It is when we know we can’t, we learn to rely on God and ask Him to do it through us. 
“With God, all things are possible!”
PH