To answer the question as to when the antichrist will be revealed, let's examine what scripture has to say (not what it does not say).Revelation 3:10 states "Since you have kept my command to endure patiently, I will keep you from the hour of trial that is going to come upon the whole world to test those who live on the earth." Jesus Christ states emphatically that the faithful will not have any part whatsoever of the Tribulation Period.
Revelation 4:1 states "After this I looked and there before me was a door standing open in heaven. And the voice I had first heard speaking to me like a trumpet said 'Come up here and I will show you what must take place after this' (my emphasis). This is Jesus speaking, and this is the Rapture of believers, followed by the Tribulation Period.
Daniel 9:27 states "He will confirm a covenant with many for one 'seven'. In the middle of the 'seven', He will put an end to sacrifice and offering (my emphasis). In other words, the antichrist will next appear to start the seven year Tribulation Period by confirming the convenant, and the Abomination of Desolation occurs in the middle of the 'seven'.
Revelation 6:1 - 3 states "I watched as the Lamb opened the first of the seven seals. Then I heard one of the four living creatures say in a voice like thunder 'Come!' I looked and there before me was a white horse! Its rider held a bow and he was given a crown, and he rode out as a conqueror bent on conquest." This is the AntiChrist who next is bent on conquest of the whole world. He certainly will be known by the whole world at this time. What follows is the death of 1/4 of the world's population by means of war, famine (which follows war), and plague.
II Thess. 2: 4 states "He will oppose and exalt himself over everything that is called God or is worshipped, so that he sets himself up as God's temple proclaiming himself to be God." This is the Abomination of Desolation which occurs near the middle of the Tribulation Period.
It is impossible for two dispensations to be occurring at the same time. The Dispensation of Grace cannot take place with the Dispensation of Jacob's Trouble. They are separated by the Rapture and the appearance of the AntiChrist.
Remember that all scripture is God's truth, regardless of who wrote it. If there is an apparent contradiction, then the problem lies with the reader, not with scripture.
May God bless you John!
Wes K.