Matthew 10:14
And whoever does not welcome you or listen to what you have to say, shake the dust off of your shoes as you leave that house or town. [Note: This was a Jewish custom showing disdain and intended to suggest unworthiness]
Acts 18:6
When the Jews resisted [Paul's efforts] and spoke against him and his message, he shook out his clothing [i.e., an expression of rejection and contempt] and said to them "Let your blood be on your own heads [i.e., you are responsible for whatever harm comes from your action]; I am not responsible. From now on I will go [and preach] to the Gentiles [only]."
2 Corinthians 2:15-17
For we [i.e., through our preaching] are like a fragrant incense which goes up to God, [and spreads the knowledge] of Christ among both saved and lost people.
Hebrews 2:3
how will we escape [punishment] if we neglect such a great salvation? [For it was] first announced [to people] by the Lord and then confirmed to us [i.e., the writer and other Christians] by those who heard Him [i.e., the original apostles].
Hebrews 12:25
Pay careful attention so that you do not refuse [to hear] God when He speaks to you. [See verse 9]. For if those people [i.e., the Israelites] did not escape [judgment] when they refused [to hear] Him who warned them on earth [i.e., God speaking through Moses at Mount Sinai], how much less [likely] will we escape [judgment] if we reject Him who warns from heaven [i.e., Christ]?