The Significance Of Bismillah ir rehman ir rahim

Bismillah ir  rehman ir rahim is the Arabic word which is translated in English as
" In The Name Of ALLAH the Beneficent, the Merciful"

Bismillah plays an important role in the life of Muslims and Islamic culture. Following the practice of the Holy Prophet Mohammad (pbuh) , Muslims begin with the name of Allah before doing anything. Bismillah occurs at the beginning of every chapter (surah) in the Holy Quran with the exception of chapter 9, Surah Tawbah. 

It is recommended that children be taught to say Bismillah before starting any work and before eating and drinking as praising Allah our creator brings in the blessings.

The Word ALLAH, 

Allah is the personal name of God the most high, and this is the greatest name and incorporates within it all the other names of God. Allah is an independent word which is the personal name of God, and this is unique to the Arabic language as no other language has a personal name for God.

REHMAN and RAHIM,

Ar-Rehman means the beneficent and Ar-Rahim means the merciful , these are the attributes given to Allah the Almighty. 

There are many attributes given to Allah and the Quran itself says in chapter 20 verse 8

"To Him belong all the beautiful names"

Allah is beneficent means His generosity is so great that before the birth of man and without any effort or labor on man's part, the entire resources required for his sustenance were provided,as well as Allah is merciful and His mercy is granted repeatedly, 

So when a person starts a work by reciting Bismillah ar-rahman ar-rahim he acknowledges and thanks God the most high for the blessings which He has provided. 

The Holy Quran mention the story of Prophet Suleman when he wrote a letter he mentioned Bismillah in the beginning. It is mentioned in chapter27, verse29-30

"Said O chief! Surely an honorable letter has been delivered to me, Surely is is from Suleman and surely it is in the name of Allah, most Beneficent, most Merciful."

The sayings of Prophet Mohammad(pbuh) on importance of Bismillah

If a person mentions the Name of Allah upon entering his house or eating satan says, addressing his followers: You will find no where to spend the night and no dinner, But if he enters without mentioning the name of Allah satan says , you have found a place to spend the night in and if he does not mention the name of Allah at the time of eating satan says you have found a place to spend night in as well as food.  ( Sahih Muslim 2/206 ) 

If anyone of you when leaving the house says, In the name of Allah I trust in Allah, there is no power and might except Allah. Your needs shall be fulfiled, you shall be saved from difficulties and hardships. Shaitan hearing these words leaves him. ( Al-Tirmidhi 2/493 )

Say bismillah, eat with your right hand and eat what is in front of you. ( Sahih Bukhari 7/88, Sahih Muslim 2/207 )