How did Stephen get full of faith and power? He listened to the spoken Word and then acted upon it.
There is only one way you get full of faith and power. You must continually hear the Word of God and do what it says.
The Bible says that faith is only acquired by hearing, and hearing, and hearing, the Word of God.
So then faith cometh by hearing, and hearing by the word of God. Romans 10:17 KJV
Signs, wonders and miracles are the result of acting upon the Word you’ve heard.