For God gave us not a spirit of fearfulness;
but of power and love and discipline/self-control.
Just like God created the first human as Spirit, you were first created as Spirit.
You are a Spirit, you possess a body and a soul, but what sets you apart from animals and other living creatures is your Spirit. Our body might function a lot like the bodies of animals, but what makes you different form monkeys, dogs and pigs is your Spirit, which is also the eternal part of your being.
The best thing about all this is, that as born again child of God, you have Gods Spirit (God is Spirit) on the inside of you and with it all of Gods potential. That is why it's so important, that you see yourself as Spirit and not as temporary body and unstable soul anymore.
With that understanding, it becomes clear why Jesus told you to do the same things as He did and even greater things than those.
Jesus did EVERYTHING He did by the same Spirit that you have on the inside. The only reason for why you haven't seen results like He has yet, is that you still see yourself as body and soul, instead of your/Gods all-mighty Spirit.
So once you come to realize that you are a Spirit and start being led by your Spirit, your soul and body will try their best to get authority over you again, but if you don't give in to them and keep being led by your perfect and whole Spirit, that Spirit will take complete authority over your feelings and your body and both will align with your Spirit!
In your Spirit you already have everything you need, because you were blessed with every spiritual blessing there is. Your Spirit is rich, healed, joyous, has peace, etc., but as long as you don't live as Spirit, all the things your Spirit has won't be able to manifest in your life. On the other hand if you start living as Spirit, your body and soul won't have a choice anymore and will have to adapt to your health, your joy, your peace and every other blessing.
Understand who you really are and what potential you have inside. Speak to your body and your soul and confess over them, that you were healed a long time ago, that you have peace and that you will live a long life, and all your spiritual blessings will show up in your body in no time!
You have great, God-given potential on the inside of you!
Realize that you are a Spirit. You possess a soul (emotions, feelings,...) and a body, but the actual you is your Spirit. That Spirit used to be weak, fearful, cowardly and blind, but now you are equipped with power, love and a sound (seeing) mind.
Start seeing yourself as who you truly are and live your life being Spirit-lead instead of feeling-lead. Live as your Spirit, in control of your soul and body, so you can leave behind the worldly weaknesses and impossibilities and start living in the SUPERNATURAL! (2. Timothy 1,7)