Mark 8:11-12; Mark 13:4; Mark 13:22; Mark 16:17; Mark 16:20

11 The Pharisees came out and began to argue with Him, seeking from Him a sign from heaven, to test Him. 12 Sighing deeply in His spirit, He said, "Why does this generation seek for a sign? Truly I say to you, no sign will be given to this generation."
4 "Tell us, when will these things be, and what will be the sign when all these things are going to be fulfilled?"
22 for false Christs and false prophets will arise, and will show signs and wonders, in order to lead astray, if possible, the elect.
17 "These signs will accompany those who have believed: in My name they will cast out demons, they will speak with new tongues;
20 And they went out and preached everywhere, while the Lord worked with them, and confirmed the word by the signs that followed.] [And they promptly reported all these instructions to Peter and his companions. And after that, Jesus Himself sent out through them from east to west the sacred and imperishable proclamation of eternal salvation. ]