according to his mercy

Titus is.a short epistle.  It is also written by Paul.  He writes to encourage him in his church leadership ministry.  Toward the end of the book, Paul makes a significant distinction between human religious effort, aka "good works", and the activity of God.  It is God's activity that is so abundant and valuable.  It is also for some reason the thing we forget about.  It's often so easy to focus on the efforts that we do, probably because it's observable and measurable.  Look up!   He has done the work!  It's all been motivated by His mercy!
​Titus 3:5 he saved us—not by works of righteousness that we had done, but according to his mercy--through the washing of regeneration and renewal by the Holy Spirit. 6 He poured out his Spirit on us abundantly through Jesus Christ our Savior 7 so that, having been justified by his grace, we may become heirs with the hope of eternal life.
Praise God!