Ephesians 1:13

1:13 And when you heard the word of truth (the gospel of your salvation) – when you believed in Christ – you were marked with the seal of the promised Holy Spirit,

Ephesians 4:29

4:29 You must let no unwholesome word come out of your mouth, but only what is beneficial for the building up of the one in need, that it may give grace to those who hear.