Is it permissible to call any of Allah's Slaves by (Rahman, Rahim, or Jabbar)
without using the definite article "Al"?
It is permissible for a person to be called by the name that corresponds to Allah's Name as long as it is not specified for Him only, such as " Al-Malik" (the King), as mentioned in the Qur'an:
And the king said: "Bring him to me."
Also such as: `Alim, Halim, Allah (Exalted be He) says:
So We gave him the glad tidings of a forbearing boy.
And they gave him glad tidings of a son having knowledge (about Allâh and His religion of True Monotheism).
(`alim). Also: Ra'uf, Rahim as He (Exalted be He) has mentioned in describing His Prophet (peace be upon him):
for the believers (he صلى الله عليه وسلم is) full of pity, kind, and merciful.
It should also be mentioned that there is a difference between the Names of the Creator (Part No. 2; Page No. 341) and the names of creations, for nothing resembles Allah (Glorified be He) in His Self, Names or Attributes. He (Exalted be He) says:
There is nothing like Him; and He is the All-Hearer, the All-Seer.
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.