Is it permissible to send children to a European school affiliated with a church, paying monthly fees, knowing that the curriculum is free from disbelief (kufr) and there is no other nearby school?

It is not primarily about where the money goes, but rather, sending children to schools that may lead them to disbelief (kufr) is a betrayal of the trust that Allah has placed upon the parent. Al-Qadi Abu Bakr Ibn al-Arabi said: "A child is a trust (amanah) with his parents, and his pure heart is a precious jewel... If he is accustomed to goodness and taught it, he will grow up upon it and be happy in this world and the Hereafter... And if he is accustomed to evil and neglected, he will be wretched and perish." The father must protect his child from the Hellfire. So how can he send him to a disbelieving teacher who instills in him love for disbelievers and moral degradation? The father must fear Allah and keep his children away from the causes of perdition, acting upon His (Allah's) saying: "O you who have believed, protect yourselves and your families from a Fire whose fuel is people and stones." It is not permissible to send children to such schools due to the prohibitions they contain, even if the curriculum is free from disbelief, for a teacher is capable of implanting disbelief and other things.