How to resynchronize all blocks using `bitcoin-cli`?
-rescan is for your wallet. It will check for missing transactions on startup. If you want to resynchronize all blocks then I think you want to use -reindex which will rebuild chain state and block index from the blk*.dat files on disk. Of course, these are command line parameters.

You can probably use verifychain on bitcoin-cli. Type bitcoin-cli help verifychain for information.