Today

I suppose this well known verse from the Psalms may sometimes be construed as a kind of Stoic philosophy.  I think it is also interpreted at times to focus on rejoicing in our daily gifts of "prosperity" in the Lord.  Even though I might be a bit inclined and even morbidly sympathetic with the Stoic point of view, I really don't believe it means either of these things.

"This is the day which the Lord hath made; we will rejoice and be glad in it." (Psalm 118:24)

I think it means exactly what it says: The Lord is God and we, and all his creation, are subject to the day he has caused.   That is the first clause.  The second clause may be more problematic for melancholic types, but it is more easily understood if the emphasis remains on the first segment - the declaration that the Lord made all, our very living and breathing.