This shouldn’t be so hard to understand what they are doing. Scriptures tell us that Satan, in subtle ways, perverts what the Scriptures say. Using some truth with deception thrown in is his way. He uses these instances to reinforce the scoffers of true Biblical truth. Rather then hate or scoff at them we should pray that the Holy Spirit opens their eyes and supports those who would be drawn into discouragement.
Are you speaking of the pre-trib rapture doctrine of Darby and Scofield based on the radical Israel/Church distinction?
A perversion of the doctrine of Christ's Second Coming and the unity of the covenant people of God.