Acts 1:1-2:

The former treatise have I made, O Theophilus, of all that Jesus began both to do and teach,
Until the day in which he was taken up, after that he through the Holy Ghost had given commandments unto the apostles whom he had chosen:

See also:

Jesus the Healer Has Never Changed
Jesus, the Best Faith Teacher
The Power in the Name of Jesus
Is It Technically Incorrect to Say That Jesus Still Heals Today?
Objection: Isaiah 53:4 (Matthew 8:17) Was Fulfilled in Jesus’ Earth Ministry and Cannot Be Claimed as a Promise by Christians
Objection: Jesus Did No More Healing Miracles After He Rose from the Dead