Peter tells the persecuted believers, i.e. Christians, that the scoffers will come and mock the idea that the Lord will return.
I don't know if he'll come back but he certainly was wrong about when. He told people of his own time that many would not taste death before the end times. Not surprising since he was an apocalyptic Jew who believed he was living in the end of this time. A belief he shared with Paul.
You are both misquoting and ignoring the context wherein they saw Jesus in the kingdom in the transfiguration vision.
Matthew 16:28-17:9
Truly I say to you that there are some of those standing here who will not taste death at all until first they see the Son of man coming in his Kingdom.”
+
17 Six days later Jesus took Peter and James and his brother John along and led them up into a lofty mountain by themselves.
+ 2 And he was transfigured before them; his face shone as the sun, and his outer garments became brilliant
* as the light.
+ 3 And look! there appeared to them Moses and E·liʹjah conversing with him.
4 Then Peter said to Jesus: “Lord, it is fine for us to be here. If you wish, I will erect three tents here, one for you, one for Moses, and one for E·liʹjah.”
5 While he was still speaking, look! a bright cloud overshadowed them, and look! a voice out of the cloud
+ said: “This is my Son, the beloved, whom I have approved.
+ Listen to him.”
+ 6 At hearing this, the disciples fell facedown and became very much afraid.
7 Then Jesus came near, and touching them, he said: “Get up. Have no fear.”
8 When they looked up, they saw no one but Jesus himself.
9 As they were descending from the mountain, Jesus commanded them: “Tell the vision to no one until the Son of man is raised up from the dead.”
+
wol.jw.org
? Thus, Peter says it to the believers the way he does. Remember prophecy is allegorical and metaphor. The rest of the Bible should be read literally. The atheists mix things up and are wrong as they usually are. Atheists are usually wrong.
