“Verily I say unto you, This generation shall not pass, till all these things be fulfilled.” (Matthew 24:34)
Based on this verse, Preterists conclude that the 70th Week of Daniel must have occurred within the lifetime of those hearing this prophecy spoken by Jesus; thus, it took place in the 1st century and is a past event from our present point of view. Matthew 10:23 and 16:28 present similar challenges that are resolved within Preterism by placing the fulfillment of prophecy in the 1st century AD.
However, the tension created by Matthew 24:34 is not resolved by conceding that its prophecy was fulfilled in the past. Such a solution creates more problems than it solves, since it is self evident that the 2nd Coming of Christ (as described in the Bible) did not occur in the 1st century. Rather, the tension is revolved by the two-fold recognition of: 1) the contingent nature of the Kingdom, and 2) the mystery nature of the Church (Age).