Wiktionary
n. (context theology English) A Christian doctrine, one of the five points of Calvinism, stating that the salvific benefit Jesus Christ's substitutionary atonement on the cross is extended to those predestined unto salvation, without any possibility of Satan or sin to successfully defeat God's election.
Wikipedia
Irresistible grace (or efficacious grace) is a doctrine in Christian theology particularly associated with Calvinism, which teaches that the saving grace of God is effectually applied to those whom He has determined to save (the elect) and, in God's timing, overcomes their resistance to obeying the call of the gospel, bringing them to faith in Christ.
Usage examples of "irresistible grace".
Her attention is fixed upon the sky, upon a silhouette of vast and irresistible grace -- metal, in her lifetime, having taught itself to fly.
They were in an immense stone chamber, one that seemed to soar skyward with irresistible grace and power and majesty.