Because the prophet Isaiah foretold the Messiah's exercise of miraculous power (Isaiah 35:4-6; 42:7), John the Baptizer asked for such a sign of Christ. Jesus replied: "The blind receive their sight and the lame walk; the lepers are cleansed and the deaf hear; the dead are raised up and the poor have the gospel preached to them" (verse 5). His miracles provided proof of who He was.
Christ came into the world, not only as God's personal representative on earth, but as God manifest in flesh. He was Himself a miracle in human form, and His miraculous works are bound up inseparably with His life. When we accept the miracles of His prophesied birth, sinless life, and glorious resurrection, then any other miracle is possible. Born holy, undefiled, and separate from sinners (Hebrews 7:26), He was conscious of His God-given responsibility to bless and relieve mankind in miraculous ways.
In describing Jesus' healing miracles, Luke, a doctor, emphasized the power of God by saying, "The power of the Lord was present to heal them" (Luke 5:17), and "the whole multitude sought to touch Him, for power went out from Him and healed them all" (Luke 6:19). Similarly in Acts, Peter describes "how God anointed Jesus of Nazareth with the Holy Spirit and with power, who went about doing good and healing all who were oppressed by the devil, for God was with Him" (Acts 10:38).
One could say Christ's miracles were parables in deeds, just as His parables were miracles in words. God designed His miracles to symbolize His power to meet spiritual needs, as well as physical and material ones. Jesus' recorded miracles are real-life experiences of what it means to be under the wonderful rule of the powerful but merciful King of God's Kingdom.