Though a short exhortation always precedes the act of confession in our Lord’s Day worship, why not place confession after the sermon? Imagine the large variety of sins that could be harvested by spending more time in the Bible field. More Spirit-inspired truth gives the Spirit more tools to dig for deep rooted sins.
There’s nothing wrong with liturgy in a different order. Revelation provides reasons to repent so presumably more revelation leads to more reasons leads to more repentance. But just as often God describes the reverse: repentance leads to accepting the truth.
Peter and James both assume that a Christian must deal with sin before consuming the Word. “Putting away all malice and all deceit and hypocrisy and envy and all slander” crave the spiritual milk (1 Peter 2:1-2). Likewise, “putting away all filthiness and rampant wickedness, receive the implanted word” (James 1:21). Sin spoils our appetite for Scripture. Sin stiff-arms the truth.
Paul presented the order even more plainly to Timothy as he explained the process for persuading opponents. Correct opponents with gentleness and “God may perhaps grant repentance leading to a knowledge of the truth” (2 Timothy 2:25). He isn’t describing the proper order of a Sunday worship service, but the principle applies. Repentance enables knowledge.
Which comes first: the understanding of truth or repentance from sin? Sometimes we don’t need more information or another sermon before we change. Sometimes we can’t see the truth because we’re clutching sin patches over our eyes. What sights we’ll see from the place of repentance.