They stand on Grace. They stand on the Rock. The Rock we stand upon is not our good works nor is it our efforts to please God. Nothing else will stand. Jesus answered and said unto them, This is the work of God, that ye believe on him whom he hath sent.
Grace is divine empowerment.
To live in this manner is to have been grounded in grace. It is strengthened not by weak fleshly will power to do good, but by His glorious power. Look how we are made fit to be heirs of His inheritance. We do not make ourselves fit through works of righteousness which we have done. God alone can make fit.