"The LORD God is my song." Odd? No! God's song of mercy is in our hearts by the Spirit's power. This pertains to spiritual exercise in that the LSB (or any hymnal) can be used thusly. Isaiah sings of the Day of Salvation and the Day of Judgment. What happens on those days? God's anger turns away from us (anger = preaching of Law) and His comfort turns toward us (preaching of Gospel).Singing in the Church is one of God's greatest gifts to us. The hymnal is intended for home use as well. It has prayers for worship, hymns (of course), and daily and weekly lectionaries (Scripture readings for each day). There are also the five settings of the Divine Service, morning and evening prayers, and mini-services (Compline, Vespers, etc.), as well as the Small Catechism (to be read and memorized).Isaiah speaks of saving water - which is the Word itself, giving eternal life! "Make known His deeds" - evangelism by living and speaking Jesus with skin on. Tell of God's saving acts - for Israelites, these include the Exodus and Jericho's fall. What has God done for you? Resurrection and adoption in Baptism; Confirmation, Holy Communion, daily breath, etc. He has acted gloriously for you - His perfection is displayed in the Cross. The Holy One is great in our midst; this One is our song.
Soli Deo gloria.