In the original koine Greek The Departure is what Paul wrote and the 'apostasia' can mean departing from the faith OR departing as in a ship disappearing over the horizon. When Jesus comes in the first Heaven to gather us to Himself, we will first be transformed to be like Him (1 John 3:2) so that we see Him as He is now. That transforming causes us to disappear from 4D spacetime in an instant, in the twinkling of an eye, and join the dead in Christ who have received their new glorified bodies as they rise to meet Jesus in the air.
In Judaism the first Heaven is the atmosphere and space surrounding our planet. Jesus is coming from the Third Heaven -the Throne Room of God- to the first Heaven and gathering us up into that first Heaven to meet Him and return to the Father's House (John14)
This not the second coming, for Jesus in His glorified body and we rising transformed beings are not visible to the world nor is He up in the air visible to the 4D earthdwellers. BUT at the Second coming every eye shall see Him!
One wonders how many dimensions there are. Cosmologist Carl Sagan famously mused about where Jesus would be, travelling at the speed of light towards the outer reaches of the Milky Way. Of course God is where ever and when ever He wants be. And in the transformation, we shall become like him. IOW, the restraints we have placed on us in this life are unleashed. In the next life Death, Time and Space would have no meaning. God is so far above our comprehension that I get a headache trying.