It’s not a religious doctrine as it is a philosophy and an outlook on how to live. It was explained in Max Weber’s magnum opus
The Protestant Work Ethic and the Spirit of Capitalism.
Although the “Protestant work ethic” isn’t a religious doctrine per se, you can’t divorce it entirely from Protestantism under the claim that “it’s
just a philosophy”. For example, many Protestant denominations teach - or are close to teaching - what is called in theology as “prosperity gospel”. Prosperity gospel teaches that financial blessing is God’s will for Christians; as such, it is inextricably predicated on the Protestant work ethic. The prosperity gospel teaching is just one of many resultant teachings in certain protestant denominations that emerge from the protestant work ethic.
The Church doesn’t really teach anything as such about the protestant work ethic, but culturally speaking (from my own experience), I would say that Catholics don’t adhere or believe in it. I used to attend a Pentecostal service alongside Mass when I was younger, and one thing I noticed was that the Pentecostal service offered meetings and appointments to deal with marriage problems, financial problems, depression, etc. The Pentecostal service really focused on the practical aspect of life. Don’t get me wrong - they explained the underpinnings of the Bible and how to live a good life and not fall into sin, but they were also aware that people had lives
outside of the service. This was in stark contrast to the Catholic Mass, which was orientated around the Eucharist and you went home straight afterwards. As I grew older, I witnessed the divergence grow. I noticed that Pentecostalism deplored suffering and promoted success whilst Catholicism deplored success and encouraged suffering. I think this divergence ultimately boils down to what part of the Bible do you emphasize most? In the Old Testament, those who were favoured in God’s sight led good lives. Illness was often perceived to be a punishment from God. Indeed, Jesus’ disciples asked him what sin a blind man must have done to have acquired his blindness, to which Jesus responds:
"“Neither this man nor his parents sinned,” said Jesus, "but this happened so that the work of God might be displayed in his life" (John 9:13). On the other hand, in the New Testament, illness is regarded as partaking in Jesus’ sacrifice. Pentecostalism focuses on the “now”, whilst Catholicism focuses on the future (Heaven).
Me, personally - I believe in the protestant work ethic. I believe the things we enjoy around us today are the result of people who work hard, and in doing so, have contributed to society. This is most exemplary in the case of science, which has prolonged and is currently prolonging human life expectancy. Even the very fact we can type on the internet is because of the intellectual contribution of computer scientists. None of this came from prayer, and none of it will come from prayer. Many historians regard Capitalism as having emerged from this very work ethic (and ironically, it’s the same system many CAF users are willing to defend to the death). Protestantism often gets a lot of bad press on this website, but perhaps you might learn a thing or two from them

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