Eyesight cannot perceive Him but He perceives eyesight. He is the All-Penetrating, the All-Aware. (Sura al-An'am: 103)
Wherever a person may be, God is surely with him. Right at this moment, as you are reading these lines, God sees you and knows exactly what crosses your mind. Wherever you go, or whatever you do, this is always the case. As the Qur'an explains:
You do not engage in any matter or recite any of the Qur'an or do any action without Our witnessing you while you are occupied with it. Not even the smallest speck eludes your Lord, either on earth or in heaven. Nor is there anything smaller than that, or larger, which is not in a Clear Book. (Sura Yunus: 61)
It is He Who created the heavens and the earth in six days, then established Himself firmly on the Throne. He knows what goes into the earth and what comes out of it, what comes down from heaven and what goes up into it. He is with you wherever you are—God sees what you do. (Sura al-Hadid: 4)
The Prophet Muhammad (saas) also reminded believers to keep this in mind when he said, "God is above the Throne and nothing is hidden from God of your deeds."
Aware of this fact, a believer submits himself to his Lord, seeks refuge in Him, and fears nothing but Him. God's command to Prophet Moses, and Aaron, who hesitated in going to Pharaoh to summon him to Islam, is a lesson for all believers:
He said, "Have no fear. I will be with you, All-Hearing and All-Seeing." (Sura Ta Ha: 46)