Reference

Philippians 1:5

For your fellowship in the gospel from the first day until now;
3

I thank my God upon every remembrance of you,

4

Always in every prayer of mine for you all making request with joy,

5

For your fellowship in the gospel from the first day until now;

6

Being confident of this very thing, that he which hath begun a good work in you will perform it until the day of Jesus Christ:

7

Even as it is meet for me to think this of you all, because I have you in my heart; inasmuch as both in my bonds, and in the defence and confirmation of the gospel, ye all are partakers of my grace.

Counter-Arguments

The strongest case that this verse does not belong in this theme.

First Day of the Week

The verse refers to "the first day until now," which signifies the beginning of their fellowship with Paul, not a specific day of the week. The phrase "first day" is used in a temporal sense to mark the start of a period, not as a calendrical reference to Sunday.