I am pretty sure about verse 3 being subjunctive mood ("optative"), though it could also be imperative: Jesus Christ, light your light for my steps.

For the first lines, my theory is:
- I hail the Holy Night
- the Holy Night gave birth to that day (Christmas, Christ, Christianity)
- I, among others, was chosen by God to behold that day.

The second verse seems to address the Holy Night as well.

I am neither a native speaker of German nor of English, but I spent a long time in either country.