Blessed (happy, fortunate, to be envied) are the undefiled (the upright, truly sincere, and blameless) in the way [of the revealed will of God], who walk (order their conduct and conversation) in the law of the Lord (the whole of God’s revealed will).
Psalm 119:1 (AMP)
When the Word of God which is the revealed will of God becomes our guide for living, we open ourselves to a life of joy and peace. When our conduct and conversation are according to His Word, we become more fully who He has called us to be, and we are no longer held in bondage to our old habbits and the tendencies of the flesh. And because of His grace, His unmerrited favor, it is never our perfect performance but much rather our sincere desire to live according to His will that makes us available to His goodness, blessings and glory.