Cracks in a wall usually mean there is something wrong with the foundation, not the wall. To put plaster over the crack does not fix the foundational issue.
In Ezekiel 13, God describes the lies of the false prophets as ‘untempered mortar’. They were daubing all the cracks in their nation with lies and feel-good messages, but something much deeper was at fault.
God says He will judge those who prophesied ‘out of their own hearts’, who followed their own spirit and had seen nothing (v.2-3). Their motivation seemed to be personal gain (v.19), not loyalty to the Lord and love for the people.
What a warning this is to us to be careful who we listen to! And to make sure that we have the right motivation when it comes to what we do. Also, it challenges us to make sure we are following the Word of God and not just what we feel in our hearts or think up in our own minds!