Most of islamic interpreters had misusderstood the word Kafir. The word kafir is to refer in reality to someone who had not even had atleast once the experience of the self as an ever existing soul, insted of a body or as a mind. This is same as the term Bramhin in hinduism. Bramhin is to refer to someone who had the realization that onself is not the body or the mind, but ever living soul or individual counciousness.
Both refer to the same meaning but one using the approach of exclusion(kafir means everyone who donot have experience of self as soul)and the other one using the approach of inclusion(bramhin means anyone who has the experience or realization of self as not the body or not the mind, but of the ever existing soul).
If you interpret the Quran in this sense, more and more things makes sense, since anyone who doesnot have this soul realization is kind of non-believer and this means 99.99 percent of muslims are non-believers. You believe something only when you exerience it and not by blind belief. Anyone who had no soul experience is to be called as kafir and may incur punishment in the kingdom of ALL PERVADING DIVINTIY. Infact, such a person who donot have a realization of self as ever living soul, will be be subjected naturally to the slavery of the nature and persecution by the nature and no need to be specifically abused by any one. The very ignorance of not realizing the self as soul is the cause of all the suffering. Vedas also affirm this.