The sixth blessing of being a child of God is joy in God. It describes an attitude of confidence in God, to rejoice in, glory in, boast in the stability of life with God. The psalmist testified of this joy in God as he made God the centre of his devotion:
Psalm 16:5-11 The LORD is the portion of mine inheritance and of my cup: thou maintainest my lot. 6 The lines are fallen unto me in pleasant places; yea, I have a goodly heritage. 7 I will bless the LORD, who hath given me counsel: my reins also instruct me in the night seasons. 8 I have set the LORD always before me: because he is at my right hand, I shall not be moved. 9 Therefore my heart is glad, and my glory rejoiceth: my flesh also shall rest in hope. 10 For thou wilt not leave my soul in hell; neither wilt thou suffer thine Holy One to see corruption. 11 Thou wilt shew me the path of life: in thy presence is fulness of joy; at thy right hand there are pleasures for evermore.
Life with God dispels fear and anxiety. We can trust in His care, provision and protection. When we look are unable to rejoice in our circumstances, we can rejoice in the Lord under those circumstances. We can rest in His love and meditate upon His goodness. It brings strength to our soul.