The Rangers have gone from being in first place by several games to being 7 games behind. I've seen the same thing hit Christians and churches. In North America, most school children are out of school in June. Bible studies are called off till the Fall. Church giving goes through the floor and worship attendance is poor.
Ministries are hard to sustain and momentum gained in the school year is lost.
Many Christians give up on their spiritual disciplines until the more regimented school year returns. Sadly, the Summer Slump involves Satan and his armies. They march out forcefully destroying marriages, ruining lives, cratering others to new addictions, and generally using the lull in spiritual passion to wrack and wreck God's unsuspecting and passionateless people. Thousands never return to their spiritual passion and their daily disciplines are forgotten completely, marriages are irrevocably ruined, and thousands of innocent lives are damaged in the wake of Satan's open door to the heart of God's people. And that's the best case scenario.