This is a hymn by the prolific hymn writer Fanny Crosby. At the time of her death, she had written something like 6000 hymns. It’s one that I associate with the evangelical camp meeting type of worship — it wasn’t in the Lutheran Book of Worship though I think it’s probably in the new cranberry-colored hymnal (which I don’t like).

Blessed assurance, Jesus is mine:
O what a foretaste of glory divine!
Heir of salvation purchase of God;
born of his Spirit, washed in his blood:

This is my story, this is my song,
praising my Savior, all the day long.

Perfect submission, perfect delight,
visions of rapture burst on my sight;
angels descending bring from above
echoes of mercy, whispers of love:

This is my story, this is my song,
praising my Savior, all the day long.

Perfect submission, all is at rest –
I in my Savior am happy and blest –
watching and waiting, looking above,
filled with his goodness, lost in his love.

This is my story, this is my song,
praising my Savior, all the day long.
(HT: Oremus)

I decided to go with the Third Day version of the hymn.