Nicodemus recognized Jesus’ miraculous from God (Jn. 2:11, 3:2) as did Peter (Acts 2:22). After Jesus’ departure, the early church, apostles, and others were administers of their share of miracles (Acts 2:43, 3:6-10, 4:30, 8:6-8, 9:40-42, et al.). Paul and his churches in Europe and Asia Minor experienced much the same (1 Cor. 12:4-31, Gal. 3:5).
A hallmark of the church of the New Testament is miracles after the ministry was gotten underway by Jesus (Luke 4:36-37). Jesus gave his authority to his disciples to heal the sick and cast out demons. These were administered not only by the Apostles but also by 70 others (Luke 10:1-19, cp. Matt. 8:10, Luke 9:49-50). This suggests their happening was also connected to the Holy Spirit that came after Pentecost. There is no reason to suspect that we have left the “age of miracles” behind us. They are reported every day.
In the Old Testament, miracles generally occurred in connection with a prominent leader – Moses, Elijah, Elisha as a sign and wonder to get Israels attention. And they succeeded, for a time.