There are churches that claim that they can speak in tongues, prophesy (predict the future directly from God), see visions etc. These are all signs and they believe that Christians can do it today.
But let’s look at how signs started. As a physical group of people, Jews required a physical proof.
Exodus 4:1-8 KJV
And Moses answered and said, But, behold, they will not believe me, nor hearken unto my voice: for they will say, The Lord hath not appeared unto thee.  And the Lord said unto him, What is that in thine hand? And he said, A rod.  And he said, Cast it on the ground. And he cast it on the ground, and it became a serpent; and Moses fled from before it.  And the Lord said unto Moses, Put forth thine hand, and take it by the tail. And he put forth his hand, and caught it, and it became a rod in his hand:  That they may believe that the Lord God of their fathers, the God of Abraham, the God of Isaac, and the God of Jacob, hath appeared unto thee.  And the Lord said furthermore unto him, Put now thine hand into thy bosom. And he put his hand into his bosom: and when he took it out, behold, his hand was leprous as snow.  And he said, Put thine hand into thy bosom again. And he put his hand into his bosom again; and plucked it out of his bosom, and, behold, it was turned again as his other flesh.  And it shall come to pass, if they will not believe thee, neither hearken to the voice of the first sign, that they will believe the voice of the latter sign.
Why did God start signs? Because of the Jews. Exodus 4 is the first time the signs happened.
These Jews were having a hard time believing.
Acts 28:27-28 KJV
For the heart of this people is waxed gross, and their ears are dull of hearing, and their eyes have they closed; lest they should see with their eyes, and hear with their ears, and understand with their heart, and should be converted, and I should heal them.  Be it known therefore unto you, that the salvation of God is sent unto the Gentiles, and that they will hear it.
So, it was always a Jewish sign back then. But what happened during the acts of the apostle? The Jews were rejecting the signs more and more. The signs were fading away during this time.
1 Corinthians 1:22-23 KJV
For the Jews require a sign, and the Greeks seek after wisdom:  But we preach Christ crucified, unto the Jews a stumblingblock, and unto the Greeks foolishness;
Christians go by faith and preaching the word of God. Jews went by sight, God says that they can see the sign. When the last apostle John died, that’s when the signs ceased less and less.