This group of favorite people is always there as per their post in every era and this will go on till the Day of Judgment. Olia ALLAH know these people by the name of Rijal Ul Gaib because they work by hiding themselves from ordinary people. They pray and they are MUTJAB UD DAWA to ALLAH and they are always busy in praying from Ummah. As per Hazrat Imam Ghazali  رحمت اللہ علیہ that any person who will recite following dua after every Namaz ALLAH will give him position of ABDAAL.

اَللّٰھُمَّ اغْفِرْ لِاُمَّۃِ مُحَّمَدٍﷺ اَللّٰھُمَّ ارْحَمْ  اُمَّۃَ مُحَّمَدٍﷺ اَللّٰھُمَّ انْصُرْ اُمَّۃَ مُحَّمَدٍ ﷺ   ABDAAL are blessings for everyone and who so ever pray for people they come close to him and in result he also comes close to them. (Aloom e Olia ALLAH Man Ziakr Abdal, Rijal Ul Gaib, Professor Sayed Ahmed Saeed Hamdani) (Selection: Usman Baig)