Narendra Modi trusts Amit Shah further than any other recognizable BJP leader due to following reasons- Amit Shah is a person who gets the work done at any cost, hook or by crook. All big leaders need a person who can apply their vision on the ground and Amit Shah does the same for Modi.
Amit Shah has been pious to Narendra Modi and they know each other for over 35 years. UPA Government pressurized Amit Shah a lot like keeping him under the bar for further than 100 days, colorful allegations, not allowed to enter Gujarat, etc. Congress wanted that Amit Shah turns against Modi and help Congress to constrain Modi fairly. But Amit Shah remained pious to Modi despite all kinds of pressure from Congress. You'll infrequently find similar fidelity in Indian politics.
Amit Shah lacks the seductiveness of Modi to come a mass leader. So, in this case, he can't hang Modi the way Modi displaced Advani as the number one leader of the BJP. Modi & BJP can survive ever with Amit Shah but Amit Shah can not survive without Modi and BJP.
Amit Shah is a master strategist. His election palm in UP in the 2014 Lok Sabha election maybe remains the stylish illustration of a successful election strategy. Amit Shah's political mind has no parallel in India moment and Modi would like to keep such an asset with him.
Modi has awarded Amit Shah for his hard work and fidelity- BJP President, Home Minister of India and number 2 politician in India. You'll infrequently find such a political brace in India where the pupil has remained pious to his schoolteacher for his whole political life.