Why do we help each other. The answer to this question is different for each person. Because each person has different reasons for example attitudes. Some men may not get a woman to sit on the bus.
To help each other. This question, each answer probably is not the same, because each person has different reasons. For example, about attitude. Some men may not stand up to the woman to sit on the bus.
Why do we have to help each other, this is a question each of them would have said are not the same. Because each of them would have a different reason for the attitude of some of the men, for example it may not be up to women sitting on the bus