How should one deal with an employee who claims to be a Muslim and prays with Muslims, but whose Qadianism has been proven, and is it permissible to prevent him from entering the mosque?

The Qadianis are disbelievers, but whoever outwardly professes Islam, denies Qadianism, and prays with us, then we must assume good about him and not accuse him of disbelief unless a Sharia judge proves his apostasy with the testimony of two just witnesses, after establishing the proof and removing any doubts. Accordingly, the aforementioned employee should be treated according to his outward appearance, and he should be allowed to pray in the mosque and have his greetings returned.