How is it that no weapon formed against you will prosper? Because you pray 10 hours a day? Because you’ve memorized the whole bible? Because you gave your whole salary in the offering? Because you honor ‘the man of God’? Big Fat NO!!
The answer lies at the end of the verse (Isaiah 54:17)
No weapon that is formed against thee shall prosper; and every tongue that shall rise against thee in judgment thou shalt condemn. This is the heritage of the servants of the LORD, AND THEIR RIGHTEOUSNESS IS OF ME, saith the LORD
Your righteousness by grace is your protection. No not your good deeds, not even your perfect obedience. Don’t get caught up in trying to win God over with your behavior to gain victory in your life. REST in Jesus and HIS righteousness, and watch every weapon formed against you fail.