Relation between men and woman

Which means:
The believing men and believing women are allies of one another. They enjoin what is right and forbid what is wrong and establish prayer and give zakāt and obey Allāh and his Messenger. Those Allāh will have mercy upon them. Indeed, Allāh is Exalted in Might and Wise.

Here Islam emphasizes the necessity of unity among the believers. Efforts to be made in establishing the peace and justice in the society jointly and unitedly both male and female are equally responsible to bring about a positive change in the society.

When Abu Lahab and his wife together causing injury to the society then Muhammad (Pbuh) Abu Bakar, Umar, Usman alone cannot face the evil power keeping behind their wives, sisters and daughters. So Khadija, Aisha, Hafsa, Sumaya, Fatima were striving together for a positive change successfully.

Relation between men and women appears clearly here in this verse. That is they are co-worker and equally responsible to do good to the humanity for their wellbeing and welfare and complementary to each other.

First of all, this is a joint responsibility of men and women to work together for constituting a world of peace and safety and security for all human being.
Secondly, in doing so there are some basic principles to be maintained. Among those principles one is:

Ibn Abbas (allah is pleased with him) said: The Messenger of Allah (Pbuh) said, “No one of you should meet a woman in privacy un less she is accompanied by a Mahram (i.e., a relative within the prohibited degrees).”
[Al-Bukhari and Muslim]

This Hadith strictly prohibits Muslim from meeting a non-Mahram woman in seclusion without her Mahram, in order to avoid the temptation to commit the sin of adultery and fornication.

As well as verse-31 of chapter Nur is giving us another fundamental principles of relation between men and women are as follows:-
Hijab is one of the blessings of Allāh for mankind which one need not to maintain with her closest ones like husbands, fathers, sons, husbands fathers, their sons, their husbands sons, brothers, brothers sons, sisters sons, their women, that which right-hand posses (i.e. slaves) or those male attendants having no physical desire, or children who are not yet aware of the private aspects of women.

This is narrated in surah Al Nur, verse 31.

Here we can learn an unique lessen from the verse. People who are subject to maintain Hijab are allowed to be married with them and people with whom you need not to maintain Hijab marriage is forbidden among them. This is very scientific and rational as well. So Islam teaches us to take the middle way rather than going to the extreme of it.

So we are learning from all these, one is the responsibility of believing men and women to make a better world for human being where we can live with peace & prosperity with all our safety & security & tranquility.

And to reach this noble goal we must not forget rules & regulations and the code of disciplines given by Allāh (SWT) and His Messenger Muhammad (Pbuh).