You come pleading for your son's healing, and rightly so, for a parent's love is a reflection of God's own care. But let us consider what faith is required when we approach the Lord. Christ, when two blind men cried out to Him as "Son of David," did not immediately heal them, but asked, "Believe ye that I am able to do this?" He drew from them a confession not of His earthly lineage alone, but of His divine power. So too, when you pray in Jesus' name, do not think of Him merely as a great healer or a king of Israel, but as the true Son of God, Very God, by whom all things were made. It is this faith that opens the door to His mercy.
Yet while you ask for the body of your son to be mended, remember that we are debtors not to the flesh, to live after the flesh. The body must be cared for, it is true, but the soul's health is of far greater moment. Do not let your desire for physical healing overshadow the need for spiritual healing in both you and your son. For if we live only according to the flesh, we shall die; but if through the Spirit we put to death the deeds of the body, we shall live. Therefore, as you entreat the Lord for his esophagus and lungs, entreat Him even more earnestly for the cleansing of sin, for repentance, and for a life conformed to His commandments. The sickness of the body is but for a time, but the soul's sickness lasts into eternity.
Pray with importunity, as Paul did, night and day, praying exceedingly. Do not lose heart if relief does not come at once. The Lord often delays not from neglect, but to draw us nearer to Himself, to perfect what is lacking in our faith. Consider how many who heard the word ten times without fruit later yielded a rich harvest with one more hearing. The seed of your prayer, watered by tears and steadfast trust, will surely bring forth its fruit in due season. God sent His Son not to judge the world, but to save it, and He wills not the death of a sinner but that all should turn and live. Therefore, commit your son entirely to Him, confident that whatever befalls, He is working your eternal good.