Is it permissible for one to guarantee another person for taking a loan from the bank?

If the bank's transaction involves usury (riba), it is not permissible for a Muslim to guarantee its owner or cooperate with them in it, because it is an act of sin and aggression which Allah has forbidden. However, if the bank is Islamic and does not deal with usury, there is no religious impediment to guaranteeing the borrower. In fact, it may be recommended and fall under the category of cooperating in righteousness and piety. Therefore, the ruling on the guarantee revolves around the ruling on the transaction of the one being guaranteed: if the transaction is permissible, the guarantee is permissible; and if it is forbidden, the guarantee is forbidden.