The Acceptable Sacrifice

Γέγραπας δηλωθῆναι σοι, δι' ἥν αἰτίαν ὁ δεῖνα παραγινόμενος τοὺς πτωχοὺς εὖ ποιῆσαι, κίνδυνον ἀργαλέον ὑπέμεινε, καὶ οὐκ ἐξείλετο αὐτὸν τῶν συμπτωμάτων ἡ πρόθεσις. Ἐπειδὴ, φημὶ, οὐ χαίρει Θεὸς ἐξ ἀδικίας θυσίαις, καὶ οὐ προσίεται κίβδηλα δῶρα. Οὐ γὰρ πᾶς ὁ βουλόμενος εὖ ποιεῖ, ἀλλ' ὁ ἀξίως Θεοῦ καὶ κτησάμενος, καὶ ἐπαγγειλάμενος τὴν θυσίαν. Ἅγιος Ἰσίδωρος Του Πηλουσιώτου, Βιβλιον Πρῶτον, Ἐπιστολὴ ΣΚΘ', Ἡρμινῳ Κομητι Source: Migne PG 78.325a

You have written to have it made clear to you how it is that he who would do well to the poor should be embroiled in tribulations and suffer grave trials, and his disposition does not save him from such occurrences. I say that God does not rejoice in an unrighteous sacrifice and does not accept base offerings. It is not everyone who wishes it that does good, but worthy of God is he who makes the promised sacrifice. Saint Isidore of Pelusium, Book 1, Letter 229, to Count Herminos