the Fatwa Department Research Committee - chaired by Sheikh `Abd al-Wahhâb al-Turayrî
It is established in the hadîth that Gabriel asked the Prophet (peace be upon him): “Tell me about excellence in faith (ihsân).”
He replied: “It is to worship Allah as though you see Him, and though you do not see Him, you know that He sees you.” [Sahîh al Bukhârî and Sahîh Muslim]
The Prophet (peace be upon him) describes excellence in faith by saying: “It is to worship Allah as though you see Him”, meaning that the worshipper engages in his worship with such acute awareness of the fact that he is presenting himself before his Lord that it is as though he sees Him. He will be absolutely sincere in his worship and his heart will be full of humility, awe, and fear. This implies that the worshipper will expend every effort in perfecting his worship.
He further describes ihsân by saying: “…and though you do not see Him, you know that He sees you.”
Some scholars, like Ibn Rajab in his work entitled Jâmi` al-`Ulûm wa al-Hikam, are of the opinion that there are two degrees of ihsân being indicated here, one stronger than the other. The strongest is to worship Allah as if you see him. If you cannot attain that level of sincerity and devotion, then at least when you worship Allah, be cognizant of the fact that He sees you.
Other scholars see only one idea being conveyed. They regard the second statement (know that He sees you) to be the cause of the first (worship Allah as though you see Him). Ibn Rajab mentions this view as well. The idea here is that the way to attain the level of worshipping Allah as though you see him is to cultivate the awareness that Allah sees you.
It is important to note that under no circumstances should this hadîth be understood to mean that Allah can be seen in this world. This is why the Prophet (peace be upon him) said: “…as though you see Him”.
And Allah knows best.
Source: Islam Today