"Sing a new song to the Lord"
    The Lord's mercies are new every day (Lamentations 3.22) and the day itself is a new gift, so our song to God should always be new, welling up out of love from our heart.  A new song is a sign our faith is alive, our relationship with Christ a
reality.  Only the lover sings.

"In the assembly of the faithful"
    Our faith calls itself to witness before others.

"Let Israel rejoice in its maker, let Zion's sons exult in their king."
    In meditating upon God as Creator and King we have two vast realities of God with which to always make our song new.  Let us turn often to the natural world to see the Creator's hand everywhere: the stars, the mountains and trees, animals and people.  Let us see the kingship of Christ in the order in which the universe is governed, the arrangement of the seasons and days and human institutions of kingship and governance which are reflections and gifts of Christ the King.  He is the Creator and King of our hearts, "to him our praise is do." (Psalm 147)

"For the Lord takes delight in his people."
    This is the inspired Word of God telling us he takes delight in us.  Why?  Because he has created us in his image and likeness.  We possess reason and free will.  The family is a reflection of the Trinity.  Man is born by means of generation, just as the Son is eternally begotten by the Father.  Our Lord once said to Padre Pio: "When I give you love you delight in me.  When you give me suffering I delight in you."

"He crowns the poor with salvation."
    "Blessed are the poor in spirit, for theirs is the kingdom of heaven." (Matthew 5.3)

"Let the faithful rejoice in their glory"
    "Rejoice in the Lord always.  I say it again, rejoice!" (Philippians for .4)

"shout for joy and take their rest."
    A final hope for eternal rest in God, whereas there is no rest day or night for the damned.  (Revelation 14.11-13)

"Let the praise of God be on their lips and a two-edged sword in their hand,"
    "Indeed, the word of God is living and active, sharper than any two-edged sword, piercing until it divides soul from spirit, joints from marrow; it is able to judge the thoughts and intentions of the heart." (Hebrews 4.12)  "Take... the sword of the Spirit, which is the Word of God." (Ephesians 6.17)

"To carry out the sentence preordained; this honor is for all his faithful."
    The elect will participate in the final judgment.  "Do you not know that the Saints will judge the world?... do you not know that we are to judge angels?" (1 Corinthians 6 .2-3)