It is sometimes claimed by pretribbers that “mysteries” of the church age do not apply to the seventieth week of Daniel, in order to maintain the church/Israel separation.
But this does not work since there are several biblical truths that reveal mysteries in the present that will transgress, and even be fulfilled, during the future seventieth week of Daniel:
“For the mystery of lawlessness is already at work; only he who now restrains will do so until he is taken out of the way.” (2 Thess 2:7)
“But in the days when the seventh angel is about to blow his trumpet, the mystery of God is completed, just as he has proclaimed to his servants the prophets.” (Rev 10:7)
“On her forehead was written a name, a mystery: ‘Babylon the Great, the Mother of prostitutes and of the detestable things of the earth.’” (Rev 17:5)
This sampling of “mysteries” demonstrates that God can deal with both the church and Israel at the same time.
A final point: Pretribbers claim that the rapture cannot occur during the “tribulation period” because the mystery age (i.e. the church) is over before then. But since the examples above demonstrate “church” mysteries will occur during the activities of the seventieth week of Daniel, then on what principle can a pretribber object to the mystery of the rapture also occurring during the seventieth week of Daniel?:
“Listen, I will tell you a mystery: We will not all sleep, but we will all be changed— in a moment, in the blinking of an eye, at the last trumpet. For the trumpet will sound, and the dead will be raised imperishable, and we will be changed.” (1 Cor 15:51–52)
 E.g. Walvoord, Rapture Question, 1st ed., 38–39.
 The Greek word mystērion is defined as: “the content of that which has not been known before but which has been revealed to an in-group or restricted constituency—‘secret, mystery.’ hymin dedotai gnōnai ta mystēria tēs basileias tōn ouranōn ‘the knowledge of the secrets of the kingdom of heaven has been given to you’ Mt 13:11. There is a serious problem involved in translating mystērion by a word which is equivalent to the English expression ‘mystery,’ for this term in English refers to a secret which people have tried to uncover but which they have failed to understand. In many instances mystērion is translated by a phrase meaning ‘that which was not known before,’ with the implication of its being revealed at least to some persons” (L&N)
 There are other mysteries that transgress the present period that will be realized as well in Daniel’s seventieth week (see Col 2:2–3; 1 Tim 3:16; Eph 1:9–10); cf. Gundry, Church and the Tribulation, 13–14.