Whose soever sins you remit, they are remitted unto them; and whose soever sins you retain, they are retained. Joh 20:23 We have the authority of Jesus while He is away.     We can do His work using His name.     This includes forgiveness of sins, casting our demons, healing sickness and disease as well as baptisms with the Holy Spirit.     We do not have the power, we simply have the authority that He has commissioned to us.     He does the work.      We are His body, His mouth, His hands and His feet, therefore we are His presence on the earth.     This privilege is not just for the clergy but for all His disciples.

As the Pharisees rightly pointed out: "who can forgive sins but God only", we see Christ the Lord giving us, His disciples, His authority to cast out sins.   

And when he had called unto him his twelve disciples, he gave them power against unclean spirits, to cast them out, and to heal all manner of sickness and all manner of disease. Mat 10:1 Jesus gives us the power of the Holy Spirit by His authority for us to heal and deliver.

The twelve (and later the seventy) went out in the authority of Christ Jesus to minister to the suffering and lost.   

Heal the sick, cleanse the lepers, raise the dead, cast out devils: freely you have received, freely give. Mat 10:8 What have we received?     All things for life and godliness 2Pe 1:3.      What are we to give?     All things for life and godliness.      Who are we to give to?     Whosoever will come to Christ Jesus in faith Rev 21:6.      Jesus wants us to administer His kingdom to those who will enter into it by faith in Him.      If you are a believer and receiver of Christ Jesus, you have all things for life and godliness in you.     You are to give out those gifts to others freely.

We give what Christ has provided by His work on His authority.   

Then Peter said, Silver and gold have I none; but such as I have give I you: In the name of Jesus Christ of Nazareth rise up and walk. Act 3:6 We cannot give what we do not have.      Peter had something.         → He had the Word Of The Lord    → He had the Holy Spirit.      The Word Of The Lord is our authority.      The Holy Spirit is our power.      When we have the Word Of The Lord in our hearts and we are filled with the Holy Spirit we have everything necessary to meet whatever need presents itself.

We see Peter giving a command to `rise up and walk` in the name of Jesus.   This is the authority of Christ operating through a disciple.   

Insomuch that they brought forth the sick into the streets, and laid them on beds and couches, that at the least the shadow of Peter passing by might overshadow some of them. Act 5:15 The people were responding in faith just as they did when Jesus walked the earth.

We see the authority of Christ and the power of the Holy Spirit issuing from Peter as he ministered.