John 5:30:

I can of mine own self do nothing: as I hear, I judge: and my judgment is just; because I seek not mine own will, but the will of the Father which hath sent me.

See also:

Do We Already Have Healing in Our Born-Again Spirits?
Objection: Jesus Healed and Did Miracles to Prove His Deity
Objection: We Cannot Expect to Heal as Jesus Did Because We Are Not the Son of God
Objection: Belief in God’s Sovereignty over Sickness and Suffering Has Proven a Tremendous Comfort to Countless Christians Through the Ages