Matthew 28:18-19 (ESV)
18 And Jesus came and said to them, “All authority in heaven and on earth has been given to me.
19 Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit,

Authority is legal or rightful power; a right to command or to act; power exercised by a person in virtue of their office or trust; to have dominion; jurisdiction; authorization; as, the authority of a prince over subjects, of parents over children and the authority of a court.
The choices we make, the things we say, the actions we take, and what we believe about what is happening around us determines whether God or Satan dominates our lives. Satan cannot control you outside of your will. He cannot do anything without your cooperation and consent. But you need to recognize that you’re in a battle and so must exercise the authority of your position in Christ Jesus.
The believer’s authority is the legal or rightful power bestowed on believers by God; with the right to command situations and the ability or strength to do something with the authority to do these things is in the name of Jesus. John 14:13. These questions are asked of believers today but unfortunately, so many are still unable to answer it or recognise and accept this authority. Matthew 21:23
When Jesus gave power and authority to the disciples over spiritual and earthly issues, He gave it to all believers. When you are born-again, you receive the Holy Spirit, who gives this power and authority to you. This authority is available through faith to all believers.
When you hold the keys to your home, cars, or office, it means you have the legal authority over them, and you have the power to decide who you allow in, so it is with the believer’s authority. The authority to change what is bound or loosed in heaven is in your hands and mouth according to Matthew 16:19.
Every believer has the power and authority to cast out demons or heal the sick, you do not need someone else to do it for you if you can exercise your spiritual or believer’s authority. You have all the spiritual power and authority to do anything Christ did and more. Jesus delegated authority and power to you Matthew 10:7-8. This way, you are not left defenceless and to the mercies of the enemy. You literally can bind the works of Satan.
So, what can you do with this authority?
You can cast out demons, heal the sick, cleanse those with skin diseases, raise the dead, speak in new tongues, tread on scorpions or serpents or be unharmed from drinking deadly things (please do not do this on purpose).
You can also take authority over the elements Mark 4:39.
You can take authority over the insects or critters that sting Luke 10:19.
You have authority for supernatural protection Proverbs 18:10.
Matthew 6:10 says you can do on earth what’s already done in heaven.
You don’t need to ask God to do this work. He won’t. Why? Because Jesus quite clearly said that you are to do the binding and losing yourself, to command evil spirits to flee. The truth is, there is a battle raging every single day in the spiritual realm. That battle is for your heart. But the Lord has given us all the authority to influence people and overthrow adversity.
Remember, you are in charge and victory is yours through Christ.
Shalom