It is taught that in our current dispensation of the Church Age, we focus on the epistles where there is virtually no mention of miracles. Yes, born-again believers do not depend on experiencing miracles. Their faith is in the Lord, regardless of whether or not they see the miraculous.
But it is entirely different in Third-World missions where we face resistance similar to that faced by the early disciples in Acts when they proclaimed the kingdom of God to the idol-worshiping gentiles who had never heard of Jesus Christ. Muslims, Hindus, Buddhists, animists, idol-worshipers and those who believe in witchcraft in many Third World nations today will not accept Jesus Christ in large numbers when the gospel is preached according to our traditional methods, typically involving humanitarian good works to show them the love of God.
But when they witness miraculous healing and the supernatural casting out of demons that their religion or gods have never done, their hearts are immediately open to the gospel of our Lord Jesus Christ. The spirit of Elijah as manifest on Mt. Carmel in 1 Kings 18 is now being restored.
During these very Last Days, when the Great Commission needs to be fulfilled to those who never heard, Acts-like miracles are being restored on the Third World mission field for those who never heard.