"genuine devotion" is an appropriate phrase for written English.
You can use it to express a sincere and deep commitment to something. For example: "He demonstrated a genuine devotion to his work, and his efforts earned him a well-deserved promotion."
Why react to genuine devotion with dread?
There are many nuns who hold fast to the church out of genuine devotion.
Shepherd simply oozed integrity and a genuine devotion to the game.
Formidable in appearance, in memory, and in mind, and fearsome of temper, he yet attracted genuine devotion and knew how to charm people.
His command of the issues, coupled with his tireless devotion to constituent concerns, underscores a genuine devotion to and eagerness to fight for his native city.
He made a point of bringing along his elder daughter, Martha (called Patsy as a girl), and later sent for his younger daughter, Maria (called Polly), all as part of his genuine devotion as a single parent.
The gritty, yet elegant, film poignantly contrasts the hypocrisy of the often brutal "Christian" adults with the genuine, spiritual devotion of children.
His determination to achieve his brothers' goals was genuine and unrelenting, his devotion to each of his own many causes over the years was sincere and unflagging.
To do this would be far from a genuine demonstration of heartfelt religious devotion.
From the moment I met him as a young governor invited to his home in Kennebunkport, I was struck by the kindness he showed to Chelsea, by his innate and genuine decency, and by his devotion to Barbara, his children, and their growing brood.
Kuhn's devotion to baseball was genuine, but his judgment was not sound.
