Merit will decline enormously once Islamic moral values have rules the world. Because there will be no pain and suffering and nothing to display fortitude over. There will be no difficulties. Everything may be delightful and easy and fine, but merit will be very low. That is why Almighty Allah is leaving it to the last moment. Almighty Allah is spreading the way of the Mahdi over 40 years so that Muslims can earn very much merit. The death of the dajjal is taking 40 years. That is explicitly stated in the hadiths. - Harun Yahya