The biggest problem of material mind is Ego.

Ego stands in direct opposition to Saint and God because ego puts its holder above them. That makes the person impervious to the teaching of God and Saint.

Ego arises from superiority complex. It fills mind with feeling of self-pride and makes mind more closed to accepting anything that goes against its ego. Sometimes it is observed that even correct and profitable options are rejected because decisions are based on ego and not on the merit of the option. One such decision is not accepting Hindu as the best religion in the world.

Ego tries to keep feeling of self-importance intact and in the process brings a lot of sufferings to the same person who pampers ego. Hindu says that no person can be non-domineering who has some materialistic possession such as beauty, power, skill, money, intellect etc. When you have these possessions people are after you for their selfish motives related to sensual happiness and material gain. The truth is people never like any person but they like possession of that person. A rich person will always be surrounded by many. Teacher, Doctor, Lawyer... everyone visits him regularly. On bankruptcy, all of them avoid him. People want their work done. But sadly, no one realizes it.

If a person has power he goes on committing crimes and says ‘Everything and everyone is purchasable.’ and later on suffers on accounts of the sins cpmmitted. Hence ego is no way a friend, yet people pamper it and the same ego puts them in trouble. Nothing is learnt from history too. Hitler had power which made him egoistic. This ego created delusions about invincibility. Ultimately the same ego destroyed Germany along with him. China is treading the same path. Chinese ego is creating delusions about invincibility of China. The end may not be much different.

The point is ego is extremely dangerous and some measures are necessary to put it down.