Question: How important is it to visit the graves of the dead? Does it make any difference to the dead ? Do they know we are there ? Or just praying for them at home will help them.  
    Answer: Visiting the graveyards has a very special significance: It reminds us of death -- the inescapable reality which every soul is bound to face. As such, we ourselves are the real beneficiaries of this visit. The Prophet (sws) has taught us to recite the following prayer when we visit the city of the dead:  

Peace be on you O dwellers of the graves; we shall be among you when Allah wishes; we beg good for you and for our ownselves from the Almighty. (Muslim, Kitabu’l Jana’iz)  

    On another occasion, he spelled out the reason for visiting the graves:  

This visit helps [us] in abstaining from worldly pleasures and in reminding [ourselves] of the Day of Judgement. (Ibn Majah, Kitabu’l Jana’iz)  

    The dead apparently do not know that we are at their graves. Their living part -- the spirit -- resides in Barzakh till the Day of Judgement.