The Indonesian term "setia" matches the English term "faithful"

other indonesian words that include "setia" : english :
setia loyal
Island Languages
There are many dialects of Indonesian that are spoken in the islands. So it is very common for people to learn their home dialect first and then learn Bahasa Indonesia once they start school.
Easy for English Speakers
English speakers who are not exposed to speaking another language until later in life find it harder to learn. But Indonesian is actually easier on English speakers compared to another language. The pronunciation of words is not as difficult, it employs Latin or Roman scripts, and Indonesian doesn’t have a lot of complex verb conjugations.
Foreign Influences
Indonesian has many loan words in it. A standard Malay Language was developed in an effort to separate the country from Dutch Colonialism. But the language still has many Dutch loanwords in it. Other languages that influence Indonesian include Sanskrit, Portuguese, Arabic, and Chinese.