Before the Sanhedrin the high priest said, "'Tell us if You are the Christ, the Son of God'" (Mt 26:63). Not only did Jesus confirm it but also said "'hereafter you will see the Son of Man sitting at the right hand of the Power, and coming on the clouds of heaven'" (:64). Afterwards at his ascension "clouds received Him out of their sight" (Ac 1:9) and "two men in white . . . [told them that Jesus] will so come in like manner as you saw Him go into heaven" (:10-11). Later Peter warned that there will be those who ask, "'Where is this 'coming' he promised?'" (2Pe 3:4 NIV). They will be those "walking according to their own lusts" (:3) saying, "'Ever since our fathers died, everything goes on as it has since the beginning of creation'" (:4 NIV). They are Jews referencing their ancestors but ignoring "that long ago by God's word the heavens existed and the earth was formed out of water and by water" (:5 NIV). Jesus had asked, "'When the Son of Man comes, will He find faith on the earth?'" (Lk 18:8) and Peter cites the lack of faith of these scoffers. He says "they deliberately" (2Pe 3:5 NIV) and "willfully forget" (:5 NKJV) "for when they maintain this, it escapes their notice" (:5 NASB). However, Paul warns that "the wrath of God is revealed from heaven against . . . [those] who suppress the truth in unrighteousness" (Ro 1:18). "Since the creation of the world His invisible attributes are clearly seen, being understood by the things that are made" (:20). Peter instructs "that you may be mindful of the words which were spoken before by the holy prophets, and the commandment of us" (2Pe 3:2). He reminds that "the Lord is not slack concerning His promise . . . [and is] not willing that any should perish but that all should come to repentance" (:9). Jesus told his disciples, "'There are some of those who are standing here who will not taste death until they see the Son of Man coming in His kingdom'" (Mt 16:28). Six days later three of them accompanied him up a mountain and "He was transfigured before them; and His face shone like the sun, and His garments became as white as light" (17:2). Peter later related that "we did not follow cleverly devised tales when we made known to you the power and coming of our Lord Jesus Christ, but we were eyewitnesses of His majesty" (2Pe 1:16). You could say that this was done as a demonstration to dispell imaginations they might have harbored. You might say Jesus had to bring "down to earth" understandings that they otherwise might incorrectly develop about heaven. He told them, "'In My Father's house are many dwelling places . . . [and] if I go prepare a place for you, I will come again and receive you to Myself, that where I am, there you may be also'" (Jn 14:2-3).
They asked, "'Tell us, when will these things happen, and what will be the sign of Your coming?'" (Mt 24:3). Jesus answered, "'This gospel of the kingdom shall [first] be preached in the whole world'" (:14). "'Then the sign of the Son of Man will appear in the sky'" (:30). However, he explained "'you do not know which day your Lord is coming'" (:42). "'For this reason you must be ready; for the Son of Man is coming at an hour when you do not think He will'" (:44). "'What I say to you I say to all, 'Be on the alert!''" (Mk 13:37). "'Blessed are those slaves whom the master will find on the alert when he comes'" (Lk 12:37). Be a person "'who knew his master's will'" (:47) because "'from everyone who has been given much, much will be required'" (:47-48). However "do not go on passing judgment before the time, but wait until the Lord comes who will" (1Co 4:5) "'bring about justice for them quickly'" (Lk 18:8). "He who is coming will come, and will not delay" (Heb 10:37). "Therefore be patient, brethren, until the coming of the Lord. The farmer waits . . . [so] you too be patient; strengthen your hearts, for the coming of the Lord is near" (Ja 5:7-8). Jesus instructed Thyatira saying, "'What you have, hold fast until I come'" (Rev 2:25). He said, "'Behold, I am coming quickly'" (22:7). He "will appear a second time for salvation without reference to sin, to those who eagerly await Him" (Heb 9:28).