Show, don't tell. Marcus Aurelius 6.27

Better to show others the good you prize than to ban them from their own goods, even when these are false.

Πῶς ὠμόν ἐστι μὴ ἐπιτρέπειν τοῖς ἀνθρώποις ὁρμᾶν ἐπὶ τὰ φαινόμενα αὐτοῖς οἰκεῖα καὶ συμφέροντα. καίτοι τρόπον τινὰ οὐ συγχωρεῖς αὐτοῖς τοῦτο ποιεῖν, ὅταν ἀγανακτῇς, ὅτι ἁμαρτάνουσι· φέρονται γὰρ πάντως ὡς ἐπὶ οἰκεῖα καὶ συμφέροντα αὐτοῖς. «ἀλλ’ οὐκ ἔχει οὕτως». οὐκοῦν δίδασκε καὶ δείκνυε μὴ ἀγανακτῶν.

How savage it is to keep men from hastening after what appears familiar and needful to them. But still you refuse to allow them this pursuit, when you are annoyed, because they are making mistakes, for they are altogether bent on what seems proper and expedient, “but that is not the way things really are!” So teach them! Show a better way, without losing your cool.