what is the name of the song that is playing while Kevin is walking to the church where he meets Marley?

The song that plays while Kevin is going into the church and then meets Marley while he's there is called “O Holy Night.”

“O Holy Night” is a well-known Weihnachten carol that was composed Von Adolphe Adam in 1847 to the French poem “Minuit, chrétiens” (Midnight, Christians) Von a wine merchant and poet, Placide Cappeau (1808 — 1877).

i have no idea but i can hum it real well