18 But what God foretold by the mouth of all the prophets, that his Christ would suffer, he thus fulfilled. 19 Repent therefore, and turn again, that your sins may be blotted out, 20 that times of refreshing may come from the presence of the Lord, and that he may send the Christ appointed for you, Jesus, 21 whom heaven must receive until the time for restoring all the things about which God spoke by the mouth of his holy prophets long ago. (Acts 3:18-21 ESV)Peter's sermon at Solomon's Portico in Acts 3 includes the curious phrase - "the time for restoring all the things about which God spoke by the mouth of the holy prophets long ago" - which indicates something very important about the coming of Christ after His first advent. There are those today - full preterists, a tiny subset of those who consider themselves Reformed - who argue that the 2nd coming foretold in Scripture occurred in 70AD when the Temple was destroyed. No doubt that event was a judgment on those who rejected Christ...no doubt that much prophecy was fulfilled in that event. How anyone can seriously regard "the restoration of all things" as having been fulfilled in that event is far beyond me.
The context of this statement promising the 'restoring all things' is the context of Old Testament prophecy, which is clear, and can readily be admitted without giving over the argument to the full preterist. The restoration of which the prophets speak is hardly exhausted in the first advent. An example of these is the prophetic words of Isaiah in chapters 65 and 66 of his prophecy... one can only read those passages as fulfilled (especially considering their repetition in 2 Peter and in Revelation) if one has presupposed that all Old Testament prophecy must somehow be fulfilled already in the age of the early church.
Christ, in Acts 3, is said not to return until the time for the restoration of all things is here. The fact that that time of restoration has obviously not yet come should be quite apparent to anyone willing to look at the world in which we live today, at post-Resurrection history from 33 AD to today, and tpo actually look at what Scripture says about that time, rather than trying to satisfy preconceived ideas by fitting Scripture into the mold defined by those preconceived ideas. Christ is still promised to be returning - at the time of restoration of all things, at which all will be put right. God's promises are yea and amen - He is faithful to fulfill ALL that He has promised.