Guidelines for spreading religious knowledge, attributed to Imam al-Sadiq ع:

“Let your [commitment] to this cause be for God, and do not make it for people, for what is [done] for God is indeed for God, and what is done for people does not rise to God.

And no not quarrel with people to [spread] your religion, for quarrelling is a cesspool for the heart.

God Almighty told his Prophet ﷺ, ‘You do not guide whom you wish; rather, God guides whom he wishes.’ He also asked him, ‘Will you coerce people until they are believers?’

Leave people be, for people take [their religion] from people, while you have taken [your religion] from the Messenger of God ﷺ.

I [once] heard my father say, “When God decrees a servant is to join this cause, he is speedier in [entering] it than a bird [returning] to its nest.”

al-Kāfi, vol.1

this tradition teaches two important points:

• Sincerity is of the essence. When one calls to the truth, it must be for God’s sake and not for other base purposes

• Quarrelling over religious matters must be avoided. Imam al-Sādiq gives three reasons for this prohibition:

- quarrelling sickens the heart, either by introducing doubt or by sowing ill will between the parties as egos flare

- quarrelling does not engender guidance, for guidance is solely in God’s hands, and the only role a person can play is in effectively communicating the truth

- arguing over relatively minor aspects of religion is pointless when the rift between a Shī’ī and a non-Shī’ī is at the fundamental level of the source of knowledge

the above translation and commentary can be found in this version of al-Kafi: https://twitter.com/jaafxr/status/1282297672364253184