By What Authority?

Act 4:6 And Annas the high priest, and Caiaphas, and John, and Alexander, and as many as were of the kindred of the high priest, were gathered together at Jerusalem.
Act 4:7 And when they had set them in the midst, they asked, By what power, or by what name, have ye done this?
Act 4:8 Then Peter, filled with the Holy Ghost, said unto them, Ye rulers of the people, and elders of Israel,
Act 4:9 If we this day be examined of the good deed done to the impotent man, by what means he is made whole;
Act 4:10 Be it known unto you all, and to all the people of Israel, that by the name of Jesus Christ of Nazareth, whom ye crucified, whom God raised from the dead, even by him doth this man stand here before you whole.
Act 4:11 This is the stone which was set at nought of you builders, which is become the head of the corner.
Act 4:12 Neither is there salvation in any other: for there is none other name under heaven given among men, whereby we must be saved.

In the name of Jesus Christ, is the authority to heal, to save the lost and to set the captives free. There were evidences of his power and authority. The evidence is in the fulfillment of the prophecy of the stone that was rejected. There was the evidence of the healing of the crippled man

Act 3:2 And a certain man lame from his mother's womb was carried, whom they laid daily at the gate of the temple which is called Beautiful, to ask alms of them that entered into the temple;
Act 3:3 Who seeing Peter and John about to go into the temple asked an alms.
Act 3:4 And Peter, fastening his eyes upon him with John, said, Look on us.
Act 3:5 And he gave heed unto them, expecting to receive something of them.
Act 3:6 Then Peter said, Silver and gold have I none; but such as I have give I thee: In the name of Jesus Christ of Nazareth rise up and walk.
Act 3:7 And he took him by the right hand, and lifted him up: and immediately his feet and ankle bones received strength.
Act 3:8 And he leaping up stood, and walked, and entered with them into the temple, walking, and leaping, and praising God.

There was the evidence of a changed life, Peter full of the Holy Ghost and power and their was the evidence of many saved of the 5000 men who heard them speak.

Act 4:3 And they laid hands on them, and put them in hold unto the next day: for it was now eventide.
Act 4:4 Howbeit many of them which heard the word believed; and the number of the men was about five thousand.

Before this there were 3000 saved.

Act 2:41 Then they that gladly received his word were baptized: and the same day there were added unto them about three thousand souls.

Act 4:18 And they called them, and commanded them not to speak at all nor teach in the name of Jesus.
Act 4:19 But Peter and John answered and said unto them, Whether it be right in the sight of God to hearken unto you more than unto God, judge ye.
Act 4:20 For we cannot but speak the things which we have seen and heard.

The powers that be, tried to shut them up. We are entering a time where there is hostility to the name and authority of Jesus. What should we do? We are told to obey the higher powers. Well, the highest power is God and the name of Jesus. We obey Him always above all other powers. Second we obey the government and authorities, if they do not impose upon our duty to God. Lastly we obey our wants and needs. Do not act foolishly in the flesh looking for trouble. Jesus gave his disciples wise advice.

Mat 10:16 Behold, I send you forth as sheep in the midst of wolves: be ye therefore wise as serpents, and harmless as doves.

Mat 28:18 And Jesus came and spake unto them, saying, All power is given unto me in heaven and in earth.
Mat 28:19 Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost:
Mat 28:20 Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you always, even unto the end of the world. Amen.