This was an act of pure mercy — of pure grace!

(George Mylne, "Reposing in Jesus: Or, The True Secret of Grace and Strength" 1862)

God might justly have left the whole race of man to perish in their sins. There was nothing to oblige God to be merciful to sinners. But God was pleased to have a chosen family in Christ Jesus. He bound Himself by the everlasting covenant . . .
  to forgive their sins,
  to renew their nature, and
  to bring them to glory!
This was an act of pure mercy — of pure grace!

"He chose us [actually picked us out for Himself as His own] in Christ before the foundation of the world, that we should be holy [consecrated and set apart for Him] and blameless in His sight." Ephesians 1:4 (Amplified Bible)