I will offer a few thoughts that help me personally in this area.
The early church was initially primarily Jewish in composition. This meant at least the opportunity, and likelihood, at least, that there would have been more of a proper understanding of the proper hermeneutic for interpreting and understanding apocalyptic language. This fundamental understanding of prophetic literature would have continued even when proselytes and God fearers (sebomai in the Greek), were converted to Christ.
However, with the conversion, and growing numbers and influence of what I personally have labelled "street Gentiles," those who had never been proselytes, or attenders of the synagogue, the purely Grecian world view and philosophy began to encroach and make inroads into the thought process of the church. The Alexandrian world view was, and remains to this day, more literalistic than Hebraic thought. The growing numbers of "street Gentiles" (pagans) meant that there was a growing ignorance of the prophetic scriptures, and a loss of the proper understanding of the correct hermeneutic for understanding the scriptures.
Also present with this growing number of "street Gentiles" and ignorance of the scripures, was a growing antipathy toward the Old Testament, and particularly toward Israel. This is seen clearly in Romans 11, (circa 55-57 A.D.), where Paul cautions the Gentiles in the body not to boast itself against Israel. The Gentile Christians had concluded, wrongly, that Israel's eschaton had already arrived and was already past (Thus, Paul's question "Has God cast off His people?" The idea that God was already through with Israel may also be involved in those who said "the resurrection is past already.")
This growing ignorance, and antipathy toward Israel and her scriptures, was part of a larger apostasy (Matthew 24:9-12; 2 Thessalonians 2:1-3) that Jesus definitely said involved misunderstandings about eschatology. There may be some subtle but important differences here between those in Thessalonians and the situation in Rome, but they are all part and parcel of the larger apostasy issue.
Jesus said that the apostasy would reach such proportions that he said the "the love of the majority of people will grow cold" (Matthew 24:12). Furthermore, he pondered about the apostasy "When the Son of Man comes, will he even find faith on the earth?" (Luke 18:8f). This is astounding. It is my conviction that the apostasy is the chief culprit to explain the silence -indeed the gross misapplication of Biblical teachings — of the apostolic and patristic writers about the parousia in A.D. 70. Consider the following.
There is nothing taught more clearly than the fact that Jerusalem was to be judged and destroyed because she had killed the prophets and of course, ultimately, killed the Lord. However, not one of the apostolic writers, (Barnabas, Hermas, Clement, etc.), and not until Justin the Martyr in approximately 150 A. D. did a single writer ever make that association!
Now, how could there be such an astounding silence, such an incredible ignorance of one of the most fundamentally significant facts of both the Old and New Testaments for that long? It was because that seemingly simple, yet incredibly important doctrine had been lost to them, even though it was right under their noses all the time!
Consider also that other issues became distorted almost immediately, without so much as a word of protest. For instance, when we read the epistles of Ignatius, his ecclesiology can be found nowhere in scripture. He said the elders stood "as God" to the church, that communion was not to be taken unless an elder gave it, and he said that there should be one bishop over an entire city. These are simply not Biblical truths. How could he have lost the truth of scriptures, writing in only 112 A.D. or so? And, why did no one chastise him for his blatant error?
Finally, it was not as if the apostasy stopped or was corrected in the patristics. Indeed, it grew worse for many centuries. The eccentricity of the patristic writers is appalling to anyone familiar with the truth of scriptures, and yet, these men are the ones that many today look to for a history of orthodoxy. This is sad indeed!
Now, do not misunderstand. I read the patristic writings regularly, and appreciate the writings and efforts of those men. However, I find their grasp of truth, in many cases to be loose. Even many of their historical claims are openly erroneous. Witness Iranaeus' claim that Jesus lived and ministered until almost 50 years old.
One thing is abundantly clear from these writings in regard to the parousia. They did associate the time of the end with the fall of Jerusalem (Epistle of Barnabas), and seemed almost perplexed that the end had not come, since they were writing after that event. Thus, there is an echo here, a faint memory perhaps, of the association of the eschaton with judgment on Israel. The early writers patently struggled to understand why the Lord had not come back, in their now distorted literalistic expectation, as they knew he had predicted. Their writings reveal this inner struggle, and their attempts to explain the so-called delay of the end (Hermas). I highly recommend Sam Frost's excellent book, Misplaced Hope. Sam documents that the apostolic writers did associate the end with A.D. 70, at least in some manner, and were trying to understand why the "end" did not occur then.
There are, perhaps, other issues involved in the silence of the early writers. However, it is my conviction that the apostasy is the main player in that silence, and in the perplexity and disappointment that they do express concerning the delay. They had lost the proper understanding of the nature of the parousia, although they certainly knew when it was supposed to have occurred, and thus failed to grasp that God had indeed kept His word. The church has been paying the price for that apostasy ever since.
In Luke 20, Jesus discussed the resurrection and the age to come.
Note that Jesus is confronted with the Sadducee's hypothetical argument against the resurrection. They discuss the practice of the Levirate marriage. Jesus, in response, says, "The sons of this age marry and are given in marriage. But those who are counted worthy to attain that age, and the resurrection from the dead, neither marry, nor are given in marriage, nor can they die...and are sons of God, being sons of the resurrection."
Please take note: Jesus said "the sons of this age marry." Jesus was referring directly to the issue of the Levirate marriage! He was not referring to the universal human experience!! It is wrong to argue "ad hominem" that "Preston is married, therefore the resurrection has not occurred," for this argument totally ignores the fact that the marriage issue at stake was the Levirate marriage law!
In what age was Jesus living, in which the Levirate marriage was the law? Clearly, it was the age of the law that was delivered to Israel at Sinai. It was the Mosaic Age!
( Deuteronomy 25)
Allow me to make three important points.
The bible speaks of only two ages, "this age," and "the age to come."
Jesus taught that "this age" was the Mosaic Age, and the age to come, was the age of Messiah and the new covenant.
Jesus believed that "this age" the age of Moses and the Law, was to end, but, the age to come was without end!
There can be no doubt as to the essential truth of these statements. And, consider that the New Testament constantly refers to the end of the Mosaic Age, but affirms repeatedly that the age of Jesus and his New Covenant is without end! (Luke 1:32-35 / Matthew 24:35 / Ephesians 3:20-21). Ask yourself therefore, if the church age has no end, how can anyone teach the end of the current Christian age?
Now to more specifically address Jesus' teaching in Luke 20.
In the age to come:
1.) They neither marry nor are given in marriage How was Jesus' this age sustained? By marrying. Jesus said in the age to come that would not be the case.
Paul said that in Christ, the age that would follow the Mosaic Age, "there is neither male or female!" (Galatians 3:28)! If, in Christ, there is neither male or female, how can there be marrying and giving in marriage? Further, Jesus said in the age to come, the Levirate marriage would not be the order of the day. Is Levirate marriage practiced under the New Covenant age of Jesus? If not, then the age to come has arrived.
2.) In the age to come they cannot die. Death was the order of the Mosaic Age. Romans 7:7f / 2 Corinthians 3:6f, (Galatians 3:20-21). In contrast, Jesus' New Covenant gives eternal life. John 8:51-Romans 6:23 / Romans 8:1-3 — free from the law of sin and death!
3.) They are Sons of God, being sons of the resurrection! Under the mosaic age — sons of god produced by giving in marrying. Born, then taught! Under the New Covenant, children are produced by faith: "you are all the children of god by faith, for as many of you as were baptized into Christ, have put on Christ." Taught, then born (Hebrews 8:6f). In Romans 6:4f, Paul speaks of death, burial and resurrection with Christ in baptism, the resurrection by faith, that produces sons of god, and life from the dead (Colossians 2:11-13).
Thus, every constituent element that Jesus said would characterize the "age to come" is found in Christ's new covenant world. And, it goes without saying that the New Covenant world followed the Mosaic world in which Jesus was living.
My final argument, therefore, has proven two things. It has proven that what the Bible calls "this age" was not the Christian age, but was in fact, the Mosaic Age, the age of the Law given to Israel at Sinai. This means, unequivocally, that the age to come, the age of the resurrection, is the Christian Age.
Second, since the resurrection was to occur at the end of Jesus' this age," and his "this age" was the Mosaic Age, then since that age came to an end at the fall of Jerusalem in A.D. 70, this means that the resurrection occurred with the fall of Jerusalem in A.D. 70.
Further, the Bible clearly presents the idea/fact of life after death, and a wonderful life, for the Christian. Don't forget that Jesus said if a person believes on him and keeps his word, "he will never die" (John 8:51). Paul anticipated his death, believing that what awaited him, in the presence of the Lord, was "far better" than even the most loving of earthly relationships (Philippians 1:20-21). He knew that at the Day of the Lord, this blessedness would be given to him (2 Timothy 4:6f). It should also be noted that in Revelation 14:13, we find the coming of Christ on the clouds, and the following statement: "Blessed are the dead that die in the Lord from henceforth, yea, says the Spirit, for they shall rest from their labors."
This verse shows us a couple of things.
First, that even after the coming of Christ on the clouds, there would be physical dying! That hardly agrees with the idea that at His coming, time ends, earth burns up, and there is no more dying.
Second, there would be a state of blessedness for those in Christ after His Coming that did not exist before it. Now, make no mistake, there has always been a difference between the "blessedness" of the death of the wicked and the righteous (see Psalms 116:15 versus Ezekiel 33:11). However, until the finished work of Christ at his parousia, even the righteous were not in the "Holy of Holies." This could only come when final judgment occurred (Revelation 15:8, and compare Revelation 16:17f).
Thus, today, when the faithful child of God dies, they enter a state of eternal blessedness that is far better than any earthly existence. Covenant Eschatology does not destroy hope, it shows us that our hope is realized in Jesus!