All perfect praise be to Allah, The Lord of The Worlds, and may His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
According to Sharia, every responsible Muslim must know Allah, The Almighty, because He said {what means}: " Know, therefore, that there is no god but God" {Muhammad/19], and He also said {what means} : " Know ye (all) that God giveth life to the earth after its death! already have We shown the Signs plainly to you, that ye may learn wisdom."{Iron/17}.
Knowing Allah is affirming His perfect attributes that must exist in Him, denying the imperfect attributes that are impossible to exist in Him, and judging that all His actions are permissible, e.g he is in charge of death and life as well as creation and resurrection. He, The Almighty, said{what means}: " That to thy Lord is the final Goal; That it is He Who granteth Laughter and Tears; That it is He Who granteth Death and Life;"{An-Najim/42-44}. From the perspective of Sharia, knowing Allah is basically attained through pondering on His signs and His great creation, and this the responsible Muslim arrives at true knowledge. Accordingly, since pondering on that which leads to this knowledge is obligatory, what it rests on is obligatory as well. Allah, The Almighty, said in this regard{what means}: " Do they not look at the Camels, how they are made?-"{Al-Ghashiya/17}. For more reading, refer to "Shareh Al-Maqasid Fi Elm Al-Kalam, (1/45)" by Imam Taftanazi.
As regards the definition of a responsible Muslim, it covers every sane adult Muslim, whether male or female. For more reading, refer to "Nehayat Al-Matlab(519-520)" by Imam Al-Haramain, Al-Juwaini. Also refer to "Jawharat At-Tawheed(1/77)" by Asheikh al-Baijoori. Moreover, Muslim scholars stipulate that the responsible Muslim must know the fundamentals of Aqeeda; however, they are of the view that it is non-obligatory for the lay man to know its branches and their particulars .
In conclusion, every responsible Muslim, male or female, must know the attributes that must exist in Allah, such as existence, oneness, and the like. Also, he/she must deny that Allah has any attributes of His creatures. In addition, he/she must know that Allah Has the Knowledge, the Will, the Ability, the Hearing, the Seeing, the Words and the Life. He/she must also deny that He has physical features such as limitations, direction, and the like. And Allah knows best.