This is something you can't change; this is how the brain work. People are more attracted to something they see this is why kaa'ba was built, and this is also why people in the past bowed to idols: they wanted something they could actually see.
Now even if you imagine something when speaking about Allah but you believe that God has no image then this is fine. But if you believe that this is actually God you are seeing then this is sinful.
Its ABSOLUTELY wrong to make an image of Allah in your brain... Its written in Surah Iklaas Wa lam yakul-lahu kufuwan ahad meaning And there is none like unto Him. So there in nothing in the universe which can be compared to him.. what i would suggest is avoid making an image of Allah in ur brain but if u fail to then...think of pure white light coming from sky as noor or blessings or torch of Allah... you could also make a mental image of the whole universe in ur brain and tell urself i worship the creator of this universe so whenever u think of Allah u think of the creator of the universe... it completely differs from person to person .. some ppl can pray without making a image in their brain... while some do not... As long as u dont make an image of Allah himself in ur brain itz fine...
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