Rev 22:1-2, Isa 53:4-5, Mt 4:23-24
God healed the Israelites from all diseases after they had left Egypt. (Ex 15:22-26)
Ex 15:22 So Moses brought Israel from the Red sea, and they went out into the wilderness of Shur; and they went three days in the wilderness, and found no water. 23 And when they came to Marah, they could not drink of the waters of Marah, for they were bitter: therefore the name of it was called Marah. 24 And the people murmured against Moses, saying, What shall we drink? 25 And he cried unto the Lord; and the Lord shewed him a tree, which when he had cast into the waters, the waters were made sweet: there he made for them a statute and an ordinance, and there he proved them, 26 And said, If thou wilt diligently hearken to the voice of the Lord thy God, and wilt do that which is right in his sight, and wilt give ear to his commandments, and keep all his statutes, I will put none of these diseases upon thee, which I have brought upon the Egyptians: for I am the Lord that healeth thee.
In the Old Testament, it was foretold that Christ would come and take away our sufferings and die to save us. (Isa 53:4-5)
Isa 53:4 Surely he hath borne our griefs, and carried our sorrows: yet we did esteem him stricken, smitten of God, and afflicted. 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.
Jesus is the Christ who died to heal our sickness and to forgive our sins. (Matthew 4:23-24, Mark 10:45)
Matthew 4:23 And Jesus went about all Galilee, teaching in their synagogues, and preaching the gospel of the kingdom, and healing all manner of sickness and all manner of disease among the people. 24 And his fame went throughout all Syria: and they brought unto him all sick people that were taken with divers diseases and torments, and those which were possessed with devils, and those which were lunatick, and those that had the palsy; and he healed them.
Mark 10:45 For even the Son of man came not to be ministered unto, but to minister, and to give his life a ransom for many.
God and the Lamb of God, Jesus Christ, is the Healer. (Rev 22:1-2)
Rev 22:1 And he shewed me a pure river of water of life, clear as crystal, proceeding out of the throne of God and of the Lamb. 2 In the midst of the street of it, and on either side of the river, was there the tree of life, which bare twelve manner of fruits, and yielded her fruit every month: and the leaves of the tree were for the healing of the nations.