First of all, people from wealth nations and poorer ones are all human beings so it is difficult to look at, hear of or talk about people who lack education or even basic human needs like food or clothes without any sympathy and compassion. Therefore, the world powers such as The US, Japan or the EU should support the underdeveloped nations by providing food and education. Sharing for a better world is not only a good deed but a duty itself. Moreover, this help might create trade relationships among nations. Developed countries that share their wealth with poorer nations can have access to cheap labor and plentiful natural resources from the poorer nations.
Although the support from developed countries is very essential, it should stop at providing food, health care and education. Otherwise, underdeveloped countries may become dependent on the aid. This can lead to the economic and political influence. Poor nations may be forced to do what rich ones want. In addition, if the world becomes equal, it will lead to the lack of motivation. People will wait for the help and stop working.
To conclusion, in my opinion, the rich nations can encourage the poor ones best by helping them to help themselves by teaching them how to produce food effectively and how to organize an education system properly.