Paul had a vision on the road to Damascus of a light in Acts chapter 9. The people with him could audibly hear Jesus speaking.
Acts 9:7 (KJV)
7 And the men which journeyed with him stood speechless, hearing a voice, but seeing no man.
And Jesus made it clear He will be with us always even to the end of the Earth (Matthew 28:20). In a sense Jesus is always here because He's God.
I think what we refer to as the second coming is the time Jesus will come back in bodily form to set up residence on the Earth and so much more.
I think Jesus appears in person twice to the Church. Once immediately after his resurrection, once at the wrap-up.
This is what Paul means by second appearance I think.
The expression 'Second Coming' just seems plain incorrect
as Jesus also comes back in judgment.
Obviously whenever he returns in judgment he is not physically appearing to those who look for him!
Once we understand the difference between appearance and coming,
then various confusing passages can be cleared up i think.