Righteousness is to be in right standing with God, this definition is Gods to decide based on a specific series of instructions.
Galatians 5:22–25
22 But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith,
23 Meekness, temperance: against such there is no law.
24 And they that are Christ's have crucified the flesh with the affections and lusts.
25 If we live in the Spirit, let us also walk in the Spirit.
The way one becomes blameless is to listen to the voice of the Holy Spirit’s correction. The goal of righteousness is to respond to the Spirit of the Lord instantly, when the Holy Spirit gives you direction, the quicker you respond, the more frequent and louder His voice will be, which will enable you to be as blameless as possible in your daily walk.
When you make a mistake ask for forgiveness as quickly as you hear the correction, as your heart moves closer to the Lord, the fewer mistakes you will make and this is the essence of Righteousness. The main point here, is what is in your heart as the Lord Himself judges.
We cannot hide the truth from the Lord
Hebrews 4:12
For the word of God is quick, and powerful, and sharper than any twoedged sword, piercing even to the dividing asunder of soul and spirit, and of the joints and marrow, and is a discerner of the thoughts and intents of the heart.
In this regard we should not judge others in their righteousness, because we can never know that truth, we must strive to be tolerant, forgiving and not judgmental on the face of another life.