I have read that its a religious order for a woman to obey her husband whenever he asks her to come on his bed. And if she refuses and her husband spends whole night angrily then angels curse that woman. But tell me what if the husband regards her wife as a sex object? What if she doesn’t want to go to bed with him? Women are human beings not sex objects. Why has Islam ordered a wife to fulfill all the sexual desires of her husband without taking into account her own feelings?

You are probably referring to the following hadīth:

Abū Hurayrah narrated from the Prophet: If a husband calls his wife to go to bed with him and she refuses and the husband spends the night in anger [at her refusal], then the angels curse her till dawn. (Bukhārī: No. 2998)

It needs to be realized that a husband and wife, besides fulfilling various other aspects of the divine plan, are like the guardians of each other’s moral conduct. Therefore, if a husband approaches his wife to fulfill his sexual desire in normal circumstances, he would expect that she show her consent. Of course, If she is tired, ill or is not in the proper frame of mind, it is the husband who should adjust to the situation. The above quoted hadīth pertains to a refusal by the wife without any genuine reason because all directives of the Prophet (sws) have common sense exceptions.

Similarly, if a husband sees that his wife needs him for the same purpose he too should not refuse without a reason. This of course is a matter of reciprocation and is a requisite of politeness. In other words, both husband and wife are the addressee of such a directive. The reason that women are given this directive is that in societies which are not perverted it is men who generally take the initiative in matters of sexual intimacy.