The Holy Light Magic has a characteristic suited to the Church, which is that it enhances its power based on the user's faith in the Holy Light. The deeper one's faith, the stronger the Holy Light Magic, making fanatics the best users.
But conversely, without faith in the Holy Light, its power will be quite ordinary. If someone detests the Holy Light, they won't even be able to learn it and might even incur the backlash of the Holy Light Magic.
The Holy Light Church does not oppose learning other skills because the characteristic of the Holy Light Magic means that things learned by church members must be filtered, with "not affecting faith in the Holy Light" as the primary rule.
If sorcery affects a believer's faith in the Holy Light Magic, then it likely won't be allowed for elite Holy Light Knights to learn, and at most, only cannon fodder-like soldiers may learn a trick or two.
