Given the infinite number of possible alternatives available, the only way that uniformity in belief systems, regarding aspects of reality not subject to rigorous scientific experimentation, is attained is through conversion by dominant individuals or groups of submissive individuals or groups. Uniformity of some degree is essential to provide common goals and purposes and harmony of activity within a society. So the effort to provide uniformity has utilitarian components, though it usually also contains components that serve more the interests of the dominant individuals or groups.
Some attempts at conversion are arguably pure utilitarian, particularly with regard to certain interpretations of utilitarianism. For example, spreading the belief that long-term benefits should be prioritized over short-term benefits would be purely utilitarian if utilitarianism is interpreted to mean “the greatest good for the greatest number over the long term.” So the conversion of others to this belief could be characterized as purely utilitarian.
However, this example illustrates how no conversion, or motive behind a conversion, can be critically reviewed except with regard to particular goals, and the goals are arrived at by a priori desires
One other point is that those converting others to prioritize long-term benefits are more likely to create a sustainable group or society than those converting others to prioritize short-term benefits. The latter groups usually vanish from the face of the earth in the long-term and we are left with the former groups.
Humans evolved in small groups to the point that each individual knew each other individual, with emotional attachments to a significant percentage of the other individuals in the group, allowing for the formation of a cohesive and healthy unit with good prospects for survival. The development of agriculture and then civilization provided pressures for groups to merge together and become larger and larger.
Large groups allowed for economic specialization and greater control over the environment, which provided much more efficient use of resources and the accumulation of wealth. However, the anonymity and the increase in the number of emotionally detached individuals caused by the large group provided significant costs, such as a greater degree of alienation and a much higher frequency of violent and harmful acts, including parasitic acts by the strong and by the weak. The strong would use their power, usually derived from wealth they already possessed, to take the wealth created by others or otherwise abuse and control others, either directly or indirectly by controlling the government, while the weak would use their anonymity to steal the fruits of others’ labor or otherwise ignore social conventions and rules for their own benefit.
The greater problem, the more dangerous parasitism, was that presented by the parasitism of the strong, who could use their economic power and control of the government to accumulate ever more wealth and power to allow them to steal more and more over time. Though both the strong and the weak parasites somewhat diminished the motivation of others to work hard to produce value, it was the strong who provided the much greater threat to the health and welfare of a social/economic system, for they held the power to bend the societal value system to meet their needs, promoting an imprudent and self-destructive mode of behavior that emphasized the importance of using power, such as military force or violence, rather than hard work and ingenuity, in order to create wealth and reach one’s goals.