Those who are watching will understand the time of the nearness of that day.

I think clarity is needed here: Christ's sacrifice on the Cross was lifted up to Heaven, where propitiation for sins was made - this was the Gospel.

The Gospel on Earth is something else, because it pertains to the nations of Earth - each nation has its own take on the Cross.

So when people say "is Christ ruling later or is He now?" the answer is 'it depends on which Gospel you are pointing to - is it the Gospel that ended in Heaven, or one of the Gospels that started on Earth?'