Passage
That, according as it is written, Hee that reioyceth, let him reioyce in the Lord.
That, according as it is written, Hee that reioyceth, let him reioyce in the Lord.
1 Corinthians 1:29 That no flesh shoulde reioyce in his presence.
1 Corinthians 1:30 But ye are of him in Christ Iesus, who of God is made vnto vs wisedome and righteousnesse, and sanctification, and redemption,
1 Corinthians 1:31 That, according as it is written, Hee that reioyceth, let him reioyce in the Lord.
The verse centers on "written", "reioyceth", and "lord". It is saying that the verse draws attention to "written" and "reioyceth", so its meaning should be read from those terms before moving to application.
The prior verse says "But ye are of him in Christ...", giving immediate footing for "written" and "reioyceth". In 1 Corinthians context, the local focus is Christ, faith, and discipleship.
A plain takeaway is to answer the verse's own emphasis on "written" and "reioyceth" with trust shaped by these words, not by a vague optimism outside the passage.