I love R.C Sproul - he is a brilliant man.
But, I disagree with him a very major point. He believes the Rapture will take place at the mid-Point of the Tribulation, or later, depending on how you take his words.
He is absolutely in error on this, and therefore, I take many of his other teachings with a grain of salt. If he can't get this one right, then he is in major error.
Address the issue of soon and quickly and the difference in the message. It is NOT about Sproul.
Your emphasis on “when” indicates the need to be in control and have secret knowledge. We are very clearly not told when, that is not the message. But it makes us feel good to think we have that secret knowledge.
I walk away very quickly from those who emphasize WHEN.