Luke 14:34
Matthew 5:13
Colossians 4:6
Let your speech at all times be gracious and pleasant, seasoned with salt, so that you will know how to answer each one [who questions you].
Hebrews 2:4-8
[and besides this evidence] God also testifying with them [confirming the message of salvation], both by signs and wonders and by various miracles [carried out by Jesus and the apostles] and by [granting to believers the] gifts of the Holy Spirit according to His own will.