Who has ever talked about signs and wonders with people and then had somebody come up and say, "Well brother, we got to be careful because the bible says "A wicked and adulterous generation seeks after a sign"? In other words, they say that as a reason to not do signs and wonders. I think we've all met those people at some point. This is an example of people being told what to believe by their leaders and not reading their bible in context, meaning the entire passage.
What happens in the beginning of Matthew 23? Jesus heals a man's withered hand on the Sabbath in front of the Pharisees in-sighting them into a rage. Then heals all (not some) of the people who followed Him out of the temple. Then Jesus heals a demon-possessed man who was blind and mute. And then it says in verse 23, "All the people were astonished and said, “Could this be the Son of David?" The people were saying that because of the signs and wonders He was performing was making them question to themselves if Jesus was the messiah. Then, in the next verse it says, "But when the Pharisees heard this, they said, "It is only by Beelzebul, the prince of demons, that this fellow drives out demons."
The people saw the signs and were pondering. The Pharisees hearts were hard, critical, and disbelieving. Later towards the end, in verse 38 and 39, "Then some of the Pharisees and teachers of the law said to him, “Teacher, we want to see a sign from you.” He answered, “A wicked and adulterous generation asks for a sign! But none will be given it except the sign of the prophet Jonah."
Now the question is asked, why didn't Jesus say that same thing to the people who all came to Him for healing? It was because those people's hearts were not dull and hardened. They had ears to hear. They weren't skeptical and critical. When Jesus said a "Wicked and adulterous generation seeks a sign", he was referring to those unbelieving Pharisees. Those Pharisees saw all of Jesus' signs, but still chose to not believe. When they told Jesus to give them a sign, Jesus basically was saying to them, 'you saw enough, I'm not gonna jump through anymore hoops for you; your hearts are hard and will not believe even if I give you 100 signs. Your minds are already made up that I'm not the messiah.' Jesus blasts them with a harsh jab saying that the only sign you’ll get is the sign of Jonah, meaning 'Repent!'
If doing signs and wonders were for a wicked and adulterous generation then Jesus would have never commanded His disciples to perform them, nor would Jesus have done them. Jesus never told that to anybody else who sought Him for miracles. Not the Canaanite woman who wanted her daughter delivered on a demon, or Roman centurion who wanted his paralyzed servant healed, and also the 5000 starving for food, and the list goes on and on.