Since the Antichrist will destroy the Harlot at the midpoint of the Tribulation, he must use her in every way possible before that time. Here are two ways that the Antichrist will use the Harlot (the false religious system) during the first half of the Tribulation.
During the first half of the Tribulation, the main objective that the Antichrist will have, in regard to the harlot’s use, is that she will help him to control the people of the world, so that they will willingly come together in unity to serve him and do his will. Therefore, all the teachings of the harlot (the entire new religion) will be focused on that effort. Thus, I think, top leaders of the new religion will be constantly meeting together to accomplish this task.
A second thing that the beast will be encouraging the harlot to do, is to get rid of all trouble makers, mainly Christians and Jews. Yes, he will use the harlot to kill them! Just like the Catholic church of old burned many Christians alive at the stake, the new false church, which will be infused with Roman Catholic teaching (all the evil parts of it), will do the same. We know this from Revelation 17:6, where John saw that the woman (the harlot) was “drunk with the blood of the saints, and with the blood of the witnesses of Jesus.” I’m sure that Satan and the beast will deceive the world into believing that all the killings are just and necessary to establish peace on earth.