The undisputed definition of Islam by all her adherents is “submission to the will of Allah.” This divine will is outlined in the Koran and in the teachings and deeds of Muhammad, as recorded in the Hadith or Sunna.
While the Koran is considered to be the true, undiluted word of God revealed to Muhammad through the angel Gabriel, the Sunna carry less weight and have always been a cause for disagreement amongst Muslim scholars. Theologians of Islam have, however, reached consensus on the authority of a set of six volumes from the Sunna called the Sahih Sita, or authentic six.
On the issues of holy war (jihad), apostasy and the treatment of women, the Koran and Sunna are clear. It is the obligation of every Muslim to spread Islam to unbelievers first through dawa, or proselytizing, then through jihad, if the unbelievers refuse to convert. It is the obligation of the unbelievers to accept Islam. Exempted from this edict of conversion are the people of the book: Christians and Jews. Both peoples have a choice. They may adopt Islam and enjoy the same rights as other Muslims, or they may stick to their book and lead the life of a dhimmi (lower citizen). Legally, the rights of the dhimmi are not equal to those of a Muslim. For instance, a Muslim man may take a Jewish or Christian wife, but Jews and Christians are not allowed to marry Muslim women. If a Christian or a Jew kills a Muslim man, they should be killed immediately. In contrast, the blood of a Muslim should never be shed in recompense for the blood of Christians or Jews.
It is also the obligation of every Muslim to command virtue and forbid vice. Apostasy, the worst possible vice a Muslim can commit, should be punished by death. The punishment need not be carried out by a state, but can easily be enforced by civilians. When it is a question of Islamic law, justice is in the hands of every Muslim.
As for the treatment of women, in the Koran and more elaborately in the Sunna, Islam assigns to girls a position in the family that requires them to be docile, makes them dependent on their male relatives for money and gives dominion over their bodies to these same male kin. In Islam there is a strict hierarchy of subservience. First and foremost, all humans are required to be the slaves of Allah. In Muslim societies, all children must obey their parents. Beyond this, women and girls must obey and serve without question their male guardians and especially their husbands. This decree of marital obedience is not in any way reciprocal.
A woman in Islam is not competent and must always have a guardian. The responsibility of guardianship may pass from father to brother to uncle before a girl is married off, at which point she must answer to her husband. Marriage is typically arranged, with no choice given to the girl, and there is often an exchange of money in the process. Thus, under the religious rule of Islam, it is still common today that a woman’s rights are essentially sold to a man she may not know, and most likely does not love.
As for education of girls under Islam, there is a clear program of indoctrination of inequality. Under Islam, education is the passing on of the rules of submission to the will of Allah. Intrinsic in this “education” is the dictation of gender roles. Girls are instructed in subservience first to God, then to the family and finally to the husband. There is strict emphasis on modesty, defined by virginity. A Muslim girl is taught to guard fiercely her virginity as an expression of loyalty to her creator and to her family and husband.
This form of education hampers her chances of ever becoming self-reliant or financially independent. A woman’s lack of social equality and freedom is a direct consequence of the teachings of Islam. Under Islam, a wife must always ask her husband for permission and she must obey indefinitely. This stricture is lifted in the unique event that he asks her to forsake God, wherein she is allowed the right of disobedience. While it is true that in Islam, technically speaking, women have the right to trade and own property, the condition of total obedience to guardians makes this “freedom” hypothetical, at best. More here.