Basically, there are two factors, which influence anyone in this world. Attraction to opposite sex. Because of these two, one becomes selfish. So all the negative qualities arise out of this. Two countries fight because of land.
War arises because of desire for land.
For some person, attraction to money is more than that of attraction to opposite sex. For some others, it is vice versa. Therefore, on the first level we can say that if one has transcended these two he is more prepared for the spiritual kingdom. The other obstacle I think is recognizing love. What I mean to say is understanding unconditional love.