Devout means having strong religious beliefs and dedication, showing reverence or respect for a particular faith. It can also refer to someone who is deeply committed to something or someone, often with an unwavering loyalty or enthusiasm.
Usage examples
She is a devout follower of her religion, attending religious services regularly and observing all the religious customs and traditions.
The singer has a devout fan base who support her music passionately and attend all her concerts.
The young boy is a devout student, always completing his homework, participating actively in class, and striving for academic excellence.
The couple kept a devout vow to stay committed and loyal to each other through thick and thin.
He is a devout environmentalist who actively participates in campaigns and protests to protect the planet.
She is the most devout Catholic I've ever encountered (next to the nuns). (katestylepetite.com)
Turns out the man is «adopted» by a suburban family of devout Christians headed by exemplary character actors Jean Smart and Richard Jenkins. (rowthree.com)
This is less to do with immigration to the UK, which is extremely stringent, than it does to do with the fact that Muslims name their kids after a single person, as often as devout Christians named their kids after a whole host of saints. (religion.blogs.cnn.com)