The main purposes of bathing or showering are to remove dirt and odors and slough off dead skin cells — basically, to maintain good hygiene. In addition, people bathe or shower to feel clean, smell fresh, revitalize, or relax.
Bathing or showering is a personal choice with social and cultural influences. People from different countries or cultures may hold different views on personal hygiene and body aroma, none of which are right or wrong, only different. For example, Americans are smell-conscious and cleanliness-oriented ("cleanliness is next to godliness"). For some countries, attention to hygiene may not be as high a priority as food and shelter. Water may be a limited resource that they would prefer to use for drinking, cooking, and agriculture, rather than for bathing or showering. On the other hand, some individuals in other societies are highly focused on hygiene.
There may be times when other people will object, either by verbal or facial expression, to the way you smell and vice versa. If you are affected by this, and are living with someone or are in close quarters with other people on a regular basis, you may want to consider bathing more often (at least every other day), and bathing after any activity that involves perspiration (including stressful times). In addition, people can learn and understand why your hygiene practices differ.
Regarding body odor, poor or inadequate hygiene habits are not the only culprits. The consumption of strong smelling foods and their odors (including tobacco use), absorbed by clothes, hair, and skin, may also contribute to body odor. Some people may also have a physiological impairment that causes pronounced natural body odor.
Bathing or showering infrequently is not harmful. But, it is important to realize that good hygiene can help promote health and prevent disease. If it weren't for the revolutionary changes in hygiene, sanitation, and the environment at the turn of the century in the United States, certain infectious diseases would continue to be a burden on the public health of our society.