It CAN be done

Nothing.

For He is God and can do all things.

We need the power of the cross to accomplish this freedom; without it the task is impossible.

(John R. Wood, author of Ordinary Live Extraordinary Mission)

We need God. We cannot do the impossible by ourselves. That is impossible. For God and with God the impossible is possible.

Saints are proof that the impossible can be done. 
(John R. Wood) 

Meaning that God worked through these holy men and women.

Example:

St. Rita - At an early age begged her parents to allow  her to join a convent but instead they arranged a marriage for their daughter.
Rita was a wonderful mother and wife but her husband had a violent temper.
In his anger he often mistreated his wife. He taught their children his evil ways.
Paelo was stabbed to death in an ambush. Before he died Rita's prayers were answered and he repented.
However their teen aged sons wanted to seek revenge.
 Both sons died within a year of illness.
Rita joined the convent of the Augustinian nuns.
She had deep devotion to the Passion of Chris and she was quoted saying,
"Please let me suffer like you, Divine Savior."
Suddenly one of the thorns from the crucifix struck her on the forehead. It left a deep wound which did not heal and caused her much suffering for the rest of her life.
She died in 1457 and is incorruptible. Which means her body did not decay.
Through her obedience and love for God, God did amazing things with her life. He did the impossible.  
St. Rita is the patron saint of impossible cases.

And yes, saints are proof the impossible can be done. 

 "For nothing is impossible with God." 
Luke 1:37