Yes, we can have assurance of salvation. Assurance is a vital certainty. Jesus Christ has made the way of salvation so open to everyone who wants to believe in Jesus Christ as their Lord and Saviour that we can find assurance in the power and witness of the Holy Spirit. Isaiah 2 verse 17 says that in the reign of the Messiah (verse 1) ‘The work of righteousness shall be peace and the effect of righteousness shall be quietness and assurance for the rest of my life.’
Everyone who believes that Jesus is the Christ has become of child of God. And everyone who loves the Father loves the children too. We know we love God’s children if we love God and obey his commandments. Loving God means keeping His commandments is not burdensome. For every child of God defeats the evil world, and we achieve this victory through our faith (John 5 ayat 1-5). The Holy Spirit witnesses in the spirit of the Christian that they are children of God.