Summary: God used signs and wonders to endorse the Christian ministry
I. God Endorsed Jesus with Signs and Wonders
Men of Israel, listen to these words: Jesus the Nazarene, a man attested to you by God with miracles and wonders and signs which God performed through Him in your midst, just as you yourselves know. Vs. 22
A. God worked Miracles Through Jesus.
Throughout the public ministry of Jesus, the disciples had the opportunity to see first hand the signs and wonders, the miracles, which God performed through His Son Jesus. In John 3:2 (quickview)  Nicodemus came to Jesus and said, Rabbi, we know that you have come from God as a teacher; for no one can do these signs that You do unless God is with him.
The word miracles comes from the Greek dunamis which describes the powerful supernatural character of the work. Wonders is the plural of the Greek teras which describes the marveling which comes to the mind of the one who witnesses a miracle, and Signs is from the Greek semeion which gives the intent of the miracles, to point to spiritual truth.
The working of miracles through Jesus showed God the Father’s approval of the work Jesus, His Son was doing, which provides evidence that Jesus was indeed the chosen Messiah sent by God.
Some in history have tried to write out the miracle working power of Jesus, trying to explain away each and every one. It is a human tendency to try and explain away what we cannot control or identify. If the miracles of Christ are removed, there is little else left, and that would substantiate a godless society, something we know is not true. The same God who supernaturally created the universe is the same God who supernaturally intervenes in our lives with miracles, wonders and signs.
B. They were witnesses of the Miracles.
Peter makes the point that they themselves knew about the miracles. Those who had stood there were unable to claim ignorance to the truth. If they chose to reject the claims of Christ, they would be doing it not from a lack of knowledge, but for a love of sin and a hatred of God. Throughout Jesus earthly ministry, he continually came up against people who, trying to justify their own sin or practices, would come against His teachings. It is still not uncommon today. People will attempt to explain away the heart of the Gospel in order to justify their own preferences. Today, we have the Holy Spirit who testifies of the truth through us, so even when they oppose the truth, they know deep down, in the bondage’s of their lives, the truth, it is just that they don’t want to accept it as truth because it could cause them to have to make changes, sometimes radical changes, in their lifestyle.
Jesus told of this in John 15:24-25 (quickview)  If I had not come and told them all this in plain language, it wouldn’t be so bad. As it is, they have no excuse. Hate me, hate my Father—it’s all the same. If I hadn’t done what I have done among them, works no one would have ever done, they wouldn’t be to blame. But they saw the God-signs and hated anyway, both me and my Father. Interesting—they have verified the truth of their own Scriptures where it is written, ‘They hated me for no good reason.’