A Thief in the Night

Why do these things Paul speaks of need explaining these days? What are the 2 types of sinners Paul is speaking to? Is it possible to speak of any Scripture that doesn’t lead to Christ and His finished work at Calvary? How will the return of Christ be viewed by the unbelieving? What is the day of the LORD? What is the difference between inheriting the Kingdom and meriting it? What does it mean that Christ is the God-Man? Were we redeemed at the cross or are we to be redeemed in the Day of the LORD or both?