Advent, a season of joy, can be stressful as well. It's not the season to be jolly - but it is a season to be joyful, to rejoice in all things. What does this joy look like? Happiness (marked by smiles and laughter, affected by external factors) must be distinguished from joy. Joy is not an emotion, but is a fruit of faith in Christ. Through its lens, we see Jesus. Through it we see and believe that this vale of tears is temporary.
Jesus working in us gives us joy. Behind all disasters, God is still for and always with us. So why do we so often settle for less - pursuing happiness? Happiness is exactly that: a pursuit, nebulous, fleeting, never permanent. Paul, by contrast, had nothing to be happy about - yet he lived in joy. Why? God's wrath for sin was directed at and loaded on Jesus! He took your place and carried your sins. Why? For joy! He rejoices over you!
So we rejoice...in Jesus. Paul follows with "The Lord is near." You are not alone; your joy flows from this fact. He is near.
Soli Deo gloria.