Hebrews 2:1-3

That is why we must hold on all the more firmly to the truths we have heard, so that we will not be carried away. The message given to our ancestors by the angels was shown to be true, and all who did not follow it or obey it received the punishment they deserved. How, then, shall we escape if we pay no attention to such a great salvation? The Lord himself first announced this salvation, and those who heard him proved to us that it is true.