When he saw them he said to them, 'Go and show yourselves to the priests.'
And as they went they were cleansed. Then one of them, when he saw that he was healed, turned back, praising God with a loud voice; and he fell on his face at Jesus' feet, giving him thanks. Now he was a Samaritan.
Then Jesus answered, 'Were not ten cleansed? Where are the nine? Was no one found to return and give praise to God except this foreigner?' And he said to him, 'Rise and go your way; your faith has made you well.' " - Luke 17:11-19 ESV
Jesus gave all of them a gift but only one leper looked to see who it was from and found a way back.
You can look at this passage and say, 'See, We should be thankful. Many aren't thankful and I don't want to be that person.' but it just doesn't work that way.
One man saw the signature on his gift through eyes of faith.
'with Love from The Father entrusted to The Son and delivered by the Holy Spirit.'
Just like when He was healed on the way to see the priest... He was saved on the way as He went back by faith to the Son.
Grace gives us a way back to God. There is a way to respond by faith. The 'initiation comes with clarification'. God's initiations are not random acts of kindness. His love has a redemptive purpose.
Jesus paid for the sins of the whole world on the cross.. not everyone will be saved by that act.. everyone could be but not everyone will be.. it was a free gift with God's signature on it.. return to Christ and only believe.