Authenticate?

After reading this article, http://spf13.com/post/evangelism-is-not-sales/

I felt very motivated to share the definition of Authenticate. Strong’s Greek states 

Strong’s Concordance
sémeion: a sign
Original Word: σημεῖον, ου, τό
Part of Speech: Noun, Neuter
Transliteration: sémeion
Phonetic Spelling: (say-mi’-on)
Short Definition: a sign, miracle, indication
Definition: a sign, miracle, indication, mark, token.HELPS Word-studies
4592 sēmeíon – a sign (typically miraculous), given especially to confirm, corroborate or authenticate. 4592 /sēmeíon (“sign”) then emphasizes the end-purpose which exalts the one giving it. Accordingly, it is used dozens of times in the NT for what authenticates the Lord and His eternal purpose, especially by doing what mere man can not replicate of take credit for.

It is so important for us to authenticate that we are working for God’s eternal purpose, as we bring the good news.

I have a print out on my fridge from John 14:12. That scripture is my hash that can never be changed. I am authenticated.