Commentary on 2 Thessalonians 2

Is 'rapture' a word used in Scripture or made up by men? Why do so many misinterpret the Scriptures regarding Christ coming? What is the 'falling away' that Paul speaks of and why does he say it's crucial before the LORD returns? What is the 'mystery of iniquity'? What does the Word man by 'antichrist'? Why does God send 'strong delusion'? How do any 'believe' in Christ and in His power alone not only to save but to allow any to believe in Him.