26 We earnestly exhort "in the heart of Christ" ( Phil . 1. 8) those faithful of whom We have mournfully written above to come back to the path of repentance and salvation. Let them remember that, when it is necessary, one must render to Caesar what is Caesar's, and with greater reason, one must render to God what is God's (Cf. Luke 20. 25). When men demand things contrary to the Divine Will, then it is necessary to put into practice the maxim of St. Peter: "We must obey God rather than men" ( Acts 5. 29). Let them also remember that it is impossible to serve two masters, if these order things opposed to one another (Cf. Matt . 6. 24). Also at times it is impossible to please both Jesus Christ and men (Cf. Gal . 1. 10). But if it sometimes happens that he who wishes to remain faithful to the Divine Redeemer even unto death must suffer great harm, let him bear it with a strong and serene soul.
Source: Ad Sinarum Gentem (Vatican.va)