Who gets the power to heal the sick and cast out demons?

I hadn't noticed this before.

Mark 3:13-19(NKJV)

And He went up on the mountain and called to Him those He Himself wanted. And they came to Him. 

Then He appointed twelve, that they might be with Him and that He might send them out to preach, 

and to have power to heal sicknesses and to cast out demons: 

Simon, to whom He gave the name Peter; 

James the son of Zebedee and John the brother of James, to whom He gave the name Boanerges, that is, “Sons of Thunder”; 

Andrew, Philip, Bartholomew, Matthew, Thomas, James the son of Alphaeus, Thaddaeus, Simon the Canaanite; 

and Judas Iscariot, who also betrayed Him. And they went into a house.

I believe that once we accept Jesus and we receive the Holy Spirit we all get some of this power in proportion to our faith.  I hadn't noticed that at first Jesus only gave this power to His twelve disciples.