Joel: This is clearly a call to repentance – something we all need to do always. All too often we think that God has us on a thread and is eager to let us go for our transgressions, (Thank you, Jonathan Edwards!) Not so. As verse 13 points out “…for He is gracious and merciful, slow to anger and abounding in steadfast love (mercy) and relents from punishing.” The LORD is reluctant to punish us almost like a parent and child. “…Sanctify a fast” (v. 15). If you have some sackcloth and ashes, that would also be a nice touch.