They were in Scripture. They are still. It was extremely controversial. But the kingdom of God came in power and the church grew rapidly with thousands added to the faith, amid persecution. That now happens for millions of Christians today.
Some people argue that signs and wonders ceased with the passing of the apostles.
The kingdom of God is not a matter of words but of power - the power of God. Signs of the kingdom and wonders declaring the reign of God break in upon us still. We see this most powerfully in Jesus' life and ministry. He proclaimed and demonstrated the rule of God in everything - in people's lives, over demonic powers, in creation and history. It was true in the early church.