The Caught Up ( Rapture ) of 1 Thess.4:17 will happen Pre-Trib. as per 2 Thess.2:7-8 since the Holy Spirit is the restrainer working through the born again believers ( to keep evil in check till God's appointed time for the man of lawlessness [ AC ] to reveal himself to get the 7 year Trib. of Daniel 9:27 started by confirming the covenant ) that He dwells in according to 1 Cor.6:19! So this is why all of Christ's bride ( those of 1 Thess.4:17 ) are seen in Heaven getting ready for the wedding of the Lamb ( Jesus - Rev.19:7-8 ) BEFORE He makes His Post-Trib. return to earth to reign in Jerusalem as per Matt.24:29-32 in conjunction with Isaiah 24:23 & Rev.19:14-21/20:1-6! Since the Holy Spirit is Omnipresent as per Psalm 139:7, He will still be present on earth to seal those ( left behind from the Caught Up together of 1 Thess.4:17 ) who come to faith in Jesus Christ! They are called the Trib. saints and some get beheaded and resurrected as Priest ( Rev.20:4-6 ) at Christ's Post-Trib. return to reign! The surviving trib. saints will be the sheep of Matt.25:34 that inherit the Millennium kingdom that Christ & those Priests reign over for 1000 years, while Satan is bound in the pit ( Rev.20:1-3 ) so he can not deceive their nations during that reign.