I would challenge you to determine who else it can be. The verse sasy “He who now letteth”
2 Thessalonians 2:7 For the mystery of iniquity doth already work: only he who now letteth will let, until he be taken out of the way.
Therefore it can’t be the body of Christ, the church and there is no other restrainer. The only restrainer of iniquity is the Holy Spirit and His work through the church.
As I said one can draw that conclusion from that ONE VERSE. My point is we cannot be 100% certain and draw the conclusion the Holy Spirit will not testify to Jesus Christ and not indwell believers in the tribulation. That is my point. Perhaps the restraining force is the same we see in Job where God restrains Satan. Don't call me dogmatic on that either. We see the 144,000 sealed in Revelation 7. Sealed on the head. Is that the Holy Spirit? I don't know, I am not certain of that.
My other point in the previous post is we should base our conclusions on all things in Scripture on multiple evidence. The 2 Thessalonians 2:7 reference is ONE verse. If I am in error and there are others I missed let me know. I checked out Daniel 9 and did not see any reference that jumped out to support the 2 Thess 2:7 reference.
So we cannot be 100% certain that "only he who now letteth will let, until he be taken out of the way" is the Holy Spirit. It makes the most sense, but to draw another conclusion that believers in the tribulation are not preached and accept the same Gospel we do is a major stretch in my humble opinion. Not even a guy like LaHaye makes such a claim. I will add most people accuse LaHaye of being sensational so I offer a look at what someone who is tenured and published well says. That would be John F. Walvoord. He is probably the one guy everyone else lifts their dispensational ideas from in the 20th and 21st centuries:
I will add he does not see a different Gospel or people being saved by Temple worship.
So some of these posts are new, news to me. I have studied Darby, Scofield, Walvoord, J. Dwight Pentecost and even read LaHaye's non-fiction prophecy books. Not once do any of these premiere dispensationalists give an indication that the Gospel is different or temple worship is how people are saved.