Its indeed necessary [not optional] for us to think deeply about the exact condition of our Imaan. Now at the present situations, Muslim Ummah are putting hard and soul efforts for developing their careers but are they really giving equal time for thinking about Imaan?
Our Rasool Muhammad [Sallallahu Alayhi Wasallam] passed nights after nights awaking, crying, giving da'wah, fasting during hot summer, performing Salaths at nights, making Du'aa for Ummah and we, the follower of Muhammad [ Sallallahu Alayhi Wasallam] sleeping in Air Conditioning rooms without even neglecting Salath? How can we stand in front of Allah Taa'la in the day of Qiyamah!
Allah Taa'la said in Quran [059:19]
"And be not like those who forgot Allah and He caused them to forget their ownselves. Those are the Fâsiqûn (rebellious, disobedient to Allah)."
One Muslim philosopher [Rohmatullah] used to ask Allah Taa'la like "Ya Allah, eyes are in our control but we can't control our eyes. Hands are in our control but we can't resist hands of doing wrong works. Legs are in our control but we even can't control our legs of going bad places but Imaan is not in our control then how can we guard our Imaan. So Allah, please secure our Imaan with your blessings and mercy."
SubhanAllah!
So my brothers n sisters we need to be very careful to guard our Imaan from all evil works. The most evil crime is forgetting Allah Taa'la. We also need to make du'aa all time so that Allah Taa'la helps us to guard our Imaan with His own rahmat.