It is God’s will that those who are saved to KNOW they are saved.  Consider and meditate on 1 John 5:13, 20-21…

I write these things to you who believe in the name of the Son of God that you may know that you have eternal life. 20 And we know that the Son of God has come and has given us understanding, so that we may know Him who is true; and we are in Him who is true, in His Son Jesus Christ.  He is the true God and eternal life. 21 Little children, keep yourselves from idols.

First… it is proper for a person who is saved to know that they are saved and have eternal life.

Second… Jesus, the Son of God, gives understanding to those who are His so that they know they are saved.  Note: Assurance of salvation is a gift given by Jesus. (1 John 5:20 above).

Third… Assurance is knowing Christ.  This is not the same as knowing about Jesus.  Knowing Christ is a relationship

Fourth… Knowing Jesus means the person is in Him and He is in them.

Fifth… Evidence of being in Christ is fruit.  That fruit being…

* Understanding (1 John 5:20 above)…

* The presence and increasing of  love that is… patient and kind, does not envy or boast, is not arrogant or rude or selfish or irritable or resentful, does not rejoice at sin, but rejoices in truth.  It bears, believes, hopes, and endures all things.

* A desire that comes from within you to worship God… read Scripture… pray… fellowship with other believers… submit to God’s will… know Christ intimately… live every minute of your life for God’s glory.

When a person is saved… from their hear and the desire God gives them… a person can know they are saved by the fruit that He brings about in them.