ANSWER:

There’s no need to feel inferior. You must work hard to reach higher level of iman. Rejecting truth and feeling this way about Islamic knowledge is a very negative sign of hypocrisy. 

How to deal with a relative who sends a lot of long Islamic texts? I say Jazakallahukhayran every now and then, but my father who is less religious feels irritated (possibly religiously inferior) by this person. I know my beard makes him feel this sometimes. I also feel inferior sometimes when someone with higher iman lectures me.