Jews in Beroea “were more noble-minded than those in Thessalonica, for they received the word with the greatest eagerness of mind, carefully examining the Scriptures daily as to whether these things [said by Paul] were so.” The Beroeans were commended rather than rebuked for doing this.—Acts 17:10, 11.

So the Thessalonians and the Beroeans could make sure of all things, likely by checking the Greek Septuagint version of the Hebrew Scriptures. They needed to read and study the Scriptures, and so do we.