South America is a largely Catholic continent where the countries largely speak the language of their former colonizers. Similarly in Africa, many former colonies are vastly Francophone and Christian/Catholic.
By contrast, the former British India and Ceylon was left largely with the same religious and linguistic makeup that it was found in.
Religion: Majority Hindu, then Muslim, Buddhist etc. There is a Catholic minority but to my knowledge, very tiny to no Protestant makeup (religion of the English)
Language: English is definitely the second language in all former British colonies but first languages are still the original, diverse makeup of languages that were found there originally and english is a minority language vs what you find in other former colonies.
Why is this the case? Did the British intentionally not enforce their language/religion or did the people not accept it?
English is an official language in sub-Saharan countries that were colonized by the United Kingdom. I don't really know what the OP means by "second language" and "first language" in this context: in many former British possessions in sub-Saharan Africa, English is commonly used in governmental business and in many mass media publications, in part because there is more than one indigenous language commonly spoken and English has come to be seen as the way to avoid privileging one of them over the others. In some (such as Ghana and Nigeria), English is the only official language precisely for that reason.
That was somewhat the situation in India as well but in India Hindi is an official language used widely by government and spoken across much of India. In Sri Lanka, the situation fits the OP's characterization, with English only being a 'recognized language'.
This status quo in sub-Saharan Africa is not tremendously far removed from the situation in former French possessions, where French once again is a common language in mass media and government publications in part for the same reasons.
The major distinction is that the postwar French government invested heavily in encouraging sub-Saharan and Caribbean Francophone countries to retain French (and in the case of Martinique and Guadeloupe, because those countries remained part of the French state as Departments Outre-Mer). That was a difference that made something of a difference during the Cold War, but its impact is fading somewhat.
In religious terms, many Francophone countries in West Africa are either majority/nearly completely Muslim (Senegal, Guinea, Mali, Niger, Burkina Faso) or exhibit some of the same north-south differentiation between Islamic, Christian and indigenous religions common in Anglophone West Africa. (Cote d'Ivoire, Togo, Benin; Nigeria, Ghana). The distributions are a bit different from country to country, with some locally relevant histories (e.g., Voodoo in Benin, Catholicism as a major proportion of local Christianity in Cote d'Ivoire). But mostly the OP's generalizations don't hold here at all--including in regard to Anglophone Africa--one of the largest percentages of Catholics in a national population in sub-Saharan Africa is in Zambia, which was under British control (more or less) for the entire colonial era.