Arrogance or Confidence?
For you did not receive the spirit of slavery to fall back into fear, but you have received the Spirit of adoption as sons, by whom we cry, “Abba! Father!†The Spirit himself bears witness with our spirit that we are children of God,
Romans 8:15-16 ESV
Christian assurance is the belief that our salvation is presently secured in Christ’s saving work on the Cross. Therefore, we can be certain in this life that we are accepted and approved by God. Objectively and subjectively, we can experientially know that we are saved by Christ’s finished work on the Cross and by the Holy Spirit’s ongoing testimony. Christian assurance is not a form of arrogance as many suppose. Faith in God’s Word and trust in his Holy Spirit’s witness is true humility. We do not conceive it for the Lord himself gives us confidence. Certainty is not arrogance if it’s given to us by the promise of God’s Word and the witness of the Spirit.
God wants his children to be sure that they belong to him, and does not want us to remain in doubt and uncertainty. So much so, that each of the three persons of the Trinity contributes to our assurance. The witness of God the Holy Spirit confirms the word of God the Father concerning the work of God the Son. The three strong legs of this tripod make it very steady indeed.
John Stott, Your Confirmation, rev. edn. (London: Hodder and Stoughton, 1991), 36.