In the article   The Gospel Missing in John   it mentioned in the conclusion:

 

"Not one verse in John mentions the mystery gospel of the glory of the cross (Gal 6:14)."

 

So, should we not use John 1:12 & John 3:16 in leading someone to Christ?

Or, as long as we let the person know what the gospel is, e.g. from I Corinthians 15:3-4,

then using other scriptures, like those from John, is still alright?