WHY CAN HEALING HAPPEN?

Because Scripture says so. Follow the trail.

Scripture (The Word) Is From GOD
2 Timothy 3:16 
All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness:

The Word Is Life
John 6:63
It is the spirit that quickeneth; the flesh profiteth nothing: the words that I speak unto you, they are spirit, and they are life.

The Word Is Truth
John 17:16-17
They are not of the world, even as I am not of the world. [17] Sanctify them through thy truth: thy word is truth.

Know The Word
John 15:7
If ye abide in me, and my words abide in you, ye shall ask what ye will, and it shall be done unto you.

Truth Brings Freedom
John 8:32 And ye shall know the truth, and the truth shall make you free.

Christ Is In Me And Is The Same Yesterday, Today And Forever. 
Hebrews 13:8

Jesus Christ the same yesterday, and today, and forever.

Galatians 2:20
I have been crucified with Christ; it is no longer I who live, but Christ lives in me; and the life which I now live in the flesh I live by faith in the Son of God, who loved me and gave Himself for me.

Colossians 1:27
To them God willed to make known what are the riches of the glory of this mystery among the Gentiles: which is Christ in you, the hope of glory.

1 Corinthians 3:16

Know ye not that ye are the temple of God, and that the Spirit of God dwelleth in you?

Purpose Of Jesus Coming
1 John 3:8
… For this purpose the Son of God was manifested, that he might destroy the works of the devil.

So If Jesus is here to destroy the works of the devil, then sin, sickness, and disease need to bow to the name of Jesus.
We are to take the Word as the roadmap for how we are to live.
Check it out, these Scriptures are powerful especially when applied in faith!

Philippians 2:9-11
Wherefore God also hath highly exalted him, and given him a name which is above every name: That at the name of Jesus every knee should bow, of things in heaven, and things in earth, and things under the earth; And that every tongue should confess that Jesus Christ is Lord, to the glory of God the Father.

Mark 16: 17-20
And these signs shall follow them that believe; In my name shall they cast out devils; they shall speak with new tongues; They shall take up serpents; and if they drink any deadly thing, it shall not hurt them; they shall lay hands on the sick, and they shall recover. So then after the Lord had spoken unto them, he was received up into heaven, and sat on the right hand of God. And they went forth, and preached every where, the Lord working with them, and confirming the word with signs following. Amen.

John 14: 11-12
Believe me that I am in the Father, and the Father in me: or else believe me for the very works’ sake. Verily, verily, I say unto you, He that believeth on me, the works that I do shall he do also; and greater works than these shall he do; because I go unto my Father.

Luke 4:18
The Spirit of the Lord [is] upon me, because he hath anointed me to preach the gospel to the poor; he hath sent me to heal the brokenhearted, to preach deliverance to the captives, and recovering of sight to the blind, to set at liberty them that are bruised,

1 Peter 2:24 
Who his own self bare our sins in his own body on the tree, that we, being dead to sins, should live unto righteousness: by whose stripes ye were healed.
 
Isaiah 53:5
But he [was] wounded for our transgressions, [he was] bruised for our iniquities: the chastisement of our peace [was] upon him; and with his stripes we are healed.

Hebrews 11:6
But without faith [it is] impossible to please [him]: for he that cometh to God must believe that he is, and [that] he is a rewarder of them that diligently seek him.

James 5:14-16
Is any sick among you? let him call for the elders of the church; and let them pray over him, anointing him with oil in the name of the Lord: And the prayer of faith shall save the sick, and the Lord shall raise him up; and if he have committed sins, they shall be forgiven him. Confess [your] faults one to another, and pray one for another, that ye may be healed. The effectual fervent prayer of a righteous man availeth much.

 Acts 10:38
How God anointed Jesus of Nazareth with the Holy Ghost and with power: who went about doing good, and healing all that were oppressed of the devil;….
 
James 4:7-8
7 Therefore submit to God. Resist the devil and he will flee from you. 8 Draw near to God and He will draw near to you. Cleanse [your] hands, [you] sinners; and purify [your] hearts, [you] double-minded.
 
Proverbs 4:20-22
My son, attend to my words; incline thine ear unto my sayings. Let them not depart from thine eyes; keep them in the midst of thine heart. For they are life unto those that find them, and health to all their flesh.
 
I John 4:4

You are of God, little children, and have overcome them, because He who is in you is greater than he who is in the world.

Matthew 10 (Read all of Matthew 10)
10:1
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. 

10:8 
Heal the sick, cleanse the lepers, raise the dead, cast out devils: freely ye have received, freely give.

Luke 10 (read the whole chapter)
…….After these things the Lord appointed other seventy also,
10:9
And heal the sick that are therein, and say unto them, The kingdom of God is come nigh unto you.

10:17
And the seventy returned again with joy, saying, Lord, even the devils are subject unto us through thy name.
 
Luke 8:48 
And he said unto her, Daughter, be of good comfort: thy faith hath made thee whole; go in peace.
 
3 John 1:2
Beloved, I wish above all things that thou mayest prosper and be in health, even as thy soul prospereth.
 
Philippians 4:19
But my God shall supply all your need according to his riches in glory by Christ Jesus.
 
Proverbs 17:22 
A merry heart doeth good [like] a medicine: but a broken spirit drieth the bones.
 
Isaiah 41:10
Fear thou not; for I [am] with thee: be not dismayed; for I [am] thy God: I will strengthen thee; yea, I will help thee; yea, I will uphold thee with the right hand of my righteousness.
 
Isaiah 54:17
No weapon that is formed against thee shall prosper; and every tongue [that] shall rise against thee in judgment thou shalt condemn. This [is] the heritage of the servants of the LORD, and their righteousness [is] of me, saith the LORD.
 
Proverbs 16:24
Pleasant words [are as] an honeycomb, sweet to the soul, and health to the bones.
 
Matthew 11:28
Come unto me, all [ye] that labour and are heavy laden, and I will give you rest.
 
2 Corinthians 12:9
And he said unto me, My grace is sufficient for thee: for my strength is made perfect in weakness.
 
John 10:10
The thief cometh not, but for to steal, and to kill, and to destroy: I am come that they might have life, and that they might have [it] more abundantly.
 
Acts 4:30 – By stretching forth thine hand to heal; and that signs and wonders may be done by the name of thy holy child Jesus.
 
Matthew 17:20 – And Jesus said unto them, Because of your unbelief: for verily I say unto you, If ye have faith as a grain of mustard seed, ye shall say unto this mountain, Remove hence to yonder place; and it shall remove; and nothing shall be impossible unto you.
 
2 Corinthians 5:7 – (For we walk by faith, not by sight:)
 
2 Corinthians 1:3 – Blessed [be] God, even the Father of our Lord Jesus Christ, the Father of mercies, and the God of all comfort;
 
John 14:27
Peace I leave with you, my peace I give unto you: not as the world giveth, give I unto you. Let not your heart be troubled, neither let it be afraid.
  
Luke 7:7
Wherefore neither thought I myself worthy to come unto thee: but say in a word, and my servant shall be healed.
 
2 Chronicles 7:14
If my people, which are called by my name, shall humble themselves, and pray, and seek my face, and turn from their wicked ways; then will I hear from heaven, and will forgive their sin, and will heal their land.
  
Acts 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.
 
Luke 14:4
And they held their peace. And he took [him], and healed him, and let him go;
 
Luke 13:13
And he laid [his] hands on her: and immediately she was made straight, and glorified God.
 
Luke 13:12
And when Jesus saw her, he called [her to him], and said unto her, Woman, thou art loosed from thine infirmity.