Any objective reading of the gospels makes it plain that Jesus believed his parousia would happen within the lifetime of his generation.
His followers believed in his imminent return until the day of their deaths.
His false prophecy damaged the lives of his disciples in a similar way to that done by the lies of modern cults like the Watchtower. Peter and others walked out on their wives, children and businesses to follow him around Palestine. Jesus taught them to put their families and other normal concerns in second place to their task of spreading his message - which turned out to be false.
The question is what he was up to?
Did he genuinely believe his false predictions, did he paint himself into a position where he couldn't back down, or was he a charlatan?
I have my own ideas about this but I'm interested in your thoughts first.
Here are just a sample of texts to support the above. Please note I am assuming there was a Jesus of history behind the myth. If you don't agree then that's a different conversation.
Peter answered him, “We have left everything to follow you! What then will there be for us?” Jesus said to them, “Truly I tell you, at the renewal of all things, when the Son of Man sits on his glorious throne, you who have followed me will also sit on twelve thrones, judging the twelve tribes of Israel. And everyone who has left houses or brothers or sisters or father or mother or wife or children or fields for my sake will receive a hundred times as much and will inherit eternal life. - Matthew 19:27-29
When you are persecuted in one place, flee to another. Truly I tell you, you will not finish going through the towns of Israel before the Son of Man comes - Matthew 10:23
For the Son of Man is going to comein his Father’s glory with his angels, and then he will reward each person according to what they have done. “Truly I tell you, some who are standing here will not taste death before they see the Son of Man coming in his kingdom.” - Matthew 16:27,28
If anyone comes to me and does not hate father and mother, wife and children, brothers and sisters—yes, even their own life—such a person cannot be my disciple. - Luke 14:26
Immediately after the distress of those days (prediction about fall of Jerusalem) “‘the sun will be darkened, and the moon will not give its light; the stars will fall from the sky, and the heavenly bodies will be shaken.’ “Then will appear the sign of the Son of Man in heaven. And then all the peoples of the earth will mourn when they see the Son of Man coming on the clouds of heaven, with power and great glory... Truly I tell you, this generation will certainly not pass away until all these things have happened.- Matthew 24:29-34
He said to another man, “Follow me.” But he replied, “Lord, first let me go and bury my father.” Jesus said to him, “Let the dead bury their own dead, but you go and proclaim the kingdom of God.” Still another said, “I will follow you, Lord; but first let me go back and say goodbye to my family.” Jesus replied, “No one who puts a hand to the plow and looks back is fit for service in the kingdom of God.” - Luke 9:59-62