When a person becomes a Child of God, there are certain truths that God wants him to know. One of the most important of these truths for a new babe in Christ has to do with assurance of salvation.

     "These things I have written to you who believe in the 
      name of the Son of God, that you may know that you 
      have eternal life, and that you may continue to believe 
      in the name of the Son of God."
                                                        1 John 5:13

In the Greek, there are two words to know:
   1. Ginosko- to come to know (progressive knowledge which enlarges and grows as time passes)
   2. Oida- full knowledge (complete and can't be improved upon; perfect or fullness of knowledge)

Oida is the Greek word used in 1 John 5:13. It means that we have the full knowledge and full assurance that we have eternal life through Jesus Christ.