Is the one who assists in apostasy an apostate, or has he committed a grave sin?

Consent to disbelief is disbelief, as Allah Almighty says: "That is because they followed what angered Allah and disliked His pleasure, so He rendered their deeds worthless" (Quran 47:28). And the Prophet, peace and blessings be upon him, said: "If a sin is committed on earth, whoever is absent from it and consents to it is like one who witnessed it, and whoever witnesses it and dislikes it is like one who was absent from it and denounced it." Whoever consents to the disbelief, wickedness, and sins of others is not following Allah's pleasure. Aiding disbelievers in their disbelief is not considered major disbelief unless the one aiding believes it to be an act of worship and obedience to Allah. Thus, whoever helps build a church out of desire for money does not commit an act of disbelief. However, whoever believes that doing so is an act of closeness or obedience to Allah is a disbeliever. It is not permissible to rule a specific person as a disbeliever except after investigation, the fulfillment of conditions, and the absence of impediments, due to the seriousness of the matter. For "If a man says to his brother, 'O disbeliever,' then one of them has committed it. If it is as he said, otherwise it returns upon him."