Healing is a piece of heaven brought right down to the earth. In heaven there is no sickness there is no disease.
Genesis 2:4-5, 8-9 (NKJV) 4 This is the history of the heavens and the earth when they were created, in the day that the Lord God made the earth and the heavens, 5 before any plant of the field was in the earth and before any herb of the field had grown. For the Lord God had not caused it to rain on the earth, and there was no man to till the ground;
8 The Lord God planted a garden eastward in Eden, and there He put the man whom He had formed. 9 And out of the ground the Lord God made every tree grow that is pleasant to the sight and good for food. The tree of life was also in the midst of the garden, and the tree of the knowledge of good and evil.
Adam and Eve were designed to live forever because there was no sickness or disease in the earth, and they had a piece of heaven on earth with the garden that God had planted.
There was a gateway, a portal between heaven and earth and the Lord would come and visit with Adam in the cool of the evening. So, where is the tree of life now?
Revelation 2:7 New King James Version (NKJV) 7 “He who has an ear, let him hear what the Spirit says to the churches. To him who overcomes I will give to eat from the tree of life, which is in the midst of the Paradise of God.” ’