Hebrews 2:3-4

How shall we escape [appropriate retribution] if we neglect and refuse to pay attention to such a great salvation [as is now offered to us, letting it drift past us forever]? For it was declared at first by the Lord [Himself], and it was confirmed to us and proved to be real and genuine by those who personally heard [Him speak]. [Besides this evidence] it was also established and plainly endorsed by God, Who showed His approval of it by signs and wonders and various miraculous manifestations of [His] power and by imparting the gifts of the Holy Spirit [to the believers] according to His own will.