Good counsel from George Whitefield concerning ascertaining whether one is of the elect–

That great man, Dr. Isaac Watts, who was called the sweet singer of Israel, says, ‘We should go first to the grammar school of faith and repentance, before we go to the university of predestination.’ Whereas the devil would have them go first to the university, to examine whether they were elected or rejected…surely I am beloved of the Lord, if my natural enmity against the Lord is slain…if God has removed that enmity to Christ out of your hearts, surely you are one of the beloved.

Sermons, Vol 1, pp. 30-31