In Romans 14:17 we learn the Kingdom of God is …righteousness, and peace, and joy in the Holy Ghost
I have at times vacillated from knowing I am saved by faith to thinking it is about my actions, leaving a wide open door for the thief to steal. Double mindedness, especially about our salvation, will never get us anything from the Lord as James states. Peace and joy can only come as a fruit once we are firmly established (Isa 54:14) in HIS RIGHTEOUSNESS not our own righteousness.
…This is the heritage of the servants of the LORD, And their vindication (RIGHTEOUSNESS) is from Me," declares the LORD. (Isaiah 54:17 NASB emphasis mine )
"But seek first His kingdom and HIS RIGHTEOUSNESS, and all these things will be added to you. (Matt 6:33 NASB emphasis mine) Matt 6:33 is telling us the solution to fear, worry and anxiety is to seek HIS RIGHTEOUSNESS first.
And the work of righteousness (HIS RIGHTEOUSNESS) will be peace… (Isaiah 32:17 NASB emphasis mine) Isaiah 32:17 is telling us that once established in (HIS RIGHTEOUSNESS), peace will be a result of HIS RIGHTEOUSNESS.
For peace and joy to come and remain it is critical to understand that works righteousness is not even taught as an option in the Bible. We can never earn a greater degree of righteousness than what Jesus has provided.
For Christ is the end of the law for righteousness to everyone who believes. Rom 10:4 NASB
Righteousness by faith alone is an absolute truth we must never abandon no matter how hard satan tries to deceive us into looking at our faults or reading works righteousness into a verse. Once we understand this truth, the door is open for peace and joy and closed for the thief to steal it.