Precisely true.
"I tell you the truth, some who are standing here will not taste death before they see the Son of Man coming in his kingdom." -Matthew 16:28
"At that time the sign of the Son of Man will appear in the sky, and all the nations of the earth will mourn. They will see the Son of Man coming on the clouds of the sky, with power and great glory. And he will send his angels with a loud trumpet call, and they will gather his elect from the four winds, from one end of the heavens to the other. Now learn this lesson from the fig tree: As soon as its twigs get tender and its leaves come out, you know that summer is near. Even so, when you see all these things, you know that it is near, right at the door. I tell you the truth, this generation will certainly not pass away until all these things have happened. Heaven and earth will pass away, but my words will never pass away. No one knows about that day or hour, not even the angels in heaven, nor the Son, but only the Father.." -Matthew 24:30-36
"Brothers, we do not want you to be ignorant about those who fall asleep, or to grieve like the rest of men, who have no hope. We believe that Jesus died and rose again and so we believe that God will bring with Jesus those who have fallen asleep in him. According to the Lord's own word, we tell you that we who are still alive, who are left till the coming of the Lord, will certainly not precede those who have fallen asleep. For the Lord himself will come down from heaven, with a loud command, with the voice of the archangel and with the trumpet call of God, and the dead in Christ will rise first. After that, we who are still alive and are left will be caught up together with them in the clouds to meet the Lord in the air. And so we will be with the Lord forever. Therefore encourage each other with these words." -Paul's 1st letter to the Thessalonians, explaining to them what to expect, Chapter 4, verses 13 thru 18
"for you know very well that the day of the Lord will come like a thief in the night. While people are saying, "Peace and safety," destruction will come on them suddenly, as labor pains on a pregnant woman, and they will not escape. But you, brothers, are not in darkness so that this day should surprise you like a thief. You are all sons of the light and sons of the day. We do not belong to the night or to the darkness. So then, let us not be like others, who are asleep, but let us be alert and self-controlled. For those who sleep, sleep at night, and those who get drunk, get drunk at night. But since we belong to the day, let us be self-controlled, putting on faith and love as a breastplate, and the hope of salvation as a helmet. For God did not appoint us to suffer wrath but to receive salvation through our Lord Jesus Christ. He died for us so that, whether we are awake or asleep, we may live together with him. Therefore encourage one another and build each other up, just as in fact you are doing." -Paul's 1st letter to the Thessalonians (Chapter 5, verses 2-11) urging them to be on guard at all times, because he expected the second coming to happen within their lifetimes.
These were predictions made at certain time in history, and those assurances directed towards a certain community of believers who were being oppressed, and who possessed a conviction that their chosen "spiritual savior" would deliver them, and enact revenge upon their oppressors. It simply didn't happen. It is at a later point that the believers began reading into the scriptures, rather than simply reading them.
OM