It is permissible to give the zakat to the appointed person if he is trustworthy to pass it to whoever deserves it. If one is not sure of his trustworthiness, his payment of Zakat to him is invalid.
It is reported in some narrations of the Imams (peace be upon them) that a believer does not stay in hell for eternity, but is accounted for his sins in the grave or on the Sirat or by other means.
