So if Psalm 104:14-15 is talking about alcoholic wine that makes men's hearts glad, then why does it say that we are to drink wine with a merry heart in Ecclesiastes 9:7?
Ecclesiastes 9:7
"Go thy way, eat thy bread with joy, and drink thy wine with a merry heart; for God now accepteth thy works."
Did you catch that? It says we are to drink "wine" WITH a merry heart. Meaning, that the wine the Israelites drank did not automatically make their hearts merry because they had to drink their wine WITH a merry heart. For if we are to assume that all forms of wine (either freshly squeezed grape juice, i.e. new wine or fully fermented wine) are to make one's heart merry, then we must also conclude that bread makes us joyful, too. But that is not what it says here. It says eat your bread with joy and drink with a merry heart. So Psalm 104:14-15 is not the type of wine that you think it is.