This is abundantly clear in the gospel reading. The leaders of the church - the equivalents of clergy, churchwardens and PCC's in our day- thought they had it sorted. To raise the great amounts of money required to maintain the vast and beautiful Temple they had money making schemes. They forbade Roman money in the temple as unclean, and required all visitors to change their Roman money for Temple shekels, charging an expensive exchange rate. The shekels were then needed to pay a temple tax - an admission fee, if you like - and to pay for the goods on sale in the temple courts. Birds and animals for the offerings were much more expensive here than in the market, but it was likely that the priests would not accept a market purchase as pure enough, so better to pay the extra than risk having to pay twice.
Now I'm not saying there was anything wrong in raising money to pay for the upkeep of the building. It is right to keep a place of worship in good condition, worthy of worship and glorifying God. But the problem lies in the transition between relying on God's wisdom and guidance for how to raise and manage the money, and thinking that we are wise enough to know for ourselves what is best. We begin to make choices based on human preference and very soon God's place of worship has become a human institution with human priorities. In the case of the Temple, these priorities had become selfish and exploitative. They were directed at raising money, not at enhancing worship. Raising money without focussing first and wholeheartedly on worshipping the Lord our God is folly. If worship is not our purpose then we are raising the money for ourselves and we've lost sight of what matters. This happened at the Temple and it hurt Jesus deeply. His own Fathers house was being managed by people who did not pay attention to his father! It was being managed by people who in their own human wisdom thought they were doing a great job. They were raising lots of money for God's temple in an effective way - it didn't occur to them that there could be anything wrong with that. But what Jesus saw was a group of people who were making their mark but not listening to God; a group of people committed to the care of the building but not paying proper attention to the Lord who dwelt there. Their priorities were all wrong. He was furious and showed them this, symbolically crashing their human money focussed priorities down to the ground. Did that look like a foolish act? Certainly, to the temple authorities. But God's foolishness is wiser than human wisdom.
Jesus compounded this foolishness in his declaration that this temple could be destroyed and he would rebuild it in three days. The authorities saw only the building that they were so very committed to. They couldn't imagine that building coming down. For them it was unthinkable, unimaginable. They saw the temple as their point of stability and safety. It was all about the temple for them, but the temple was strong. It couldn't possibly be destroyed. They imagined it existing forever - or at least, beyond their lifetimes and that of their children, which is what most people really meant by forever. They had no concept, none at all, of God's business being separate from the building. They had created this beautiful human built edifice to contain God, and they expected to find God there. It was all about the building and they, by their human efforts, would keep that building safe. To speak of destruction sounded like nonsense.
Of course, we approach that story with the benefit of hindsight. We know that the temple was not made to last, that indeed it only had another forty years before it would be destroyed - and not rebuilt. We also know that Jesus meant his own body when he referred to destroying this temple. The dwelling place of God was no longer in a building but in a man. To the human hearer, Jesus' assertion about his bodily destruction sounds like the greatest folly of all. Paul wrote: "For the message about the cross is foolishness to those who are perishing, but to us who are being saved it is the power of God." By any human logic, the cross does not make sense. It only makes sense seen through the explanation God offers through the wisdom of the Holy Spirit. In the cross Jesus showed us how to accept death, defeat and destruction, and in the resurrection he shows us what lies beyond that destruction for those who truly worship him.
Our priority must be to worship God. However odd it sounds to those who are aware of the need to fix roofs damaged by lead thieves, or organs, or to ensure that works generated by quinquennial inspections can be paid for, these things are not our first priority, not even second or third. If we manage our money with such things as priorities then we are acting according to human wisdom. That is not good enough. We are as deserving of Jesus turning the tables on us as the temple authorities were. Rather, we must seek first God's Kingdom, and worship Him. It is not for us to focus on buildings as though they matter to God. Jesus told Peter that he, Jesus, would build his church. Not us. Jesus is the builder and we are the workforce taking his directions. If we don't work according to his priorities then the edifices we try to build and preserve according to our own wisdom will crumble and fall as thoroughly as the temple did in AD70. Jesus' design for his church is not about buildings or institutions, not about committees, meetings or minutes, not about processes set out in rule books or having reserves of money in case the tower falls down. His design is not one that human wisdom would ever come up with. It is about people, living in grace, trusting God to provide for them, being obedient to his command to love him first before all else.
God's foolishness is wiser than human wisdom, and God's weakness is stronger than human strength.