By Singing the Psalms, the Church Learns Scripture
Based on experience and existing research, we should agree that it is easier to learn songs than prose. Parts of the human brain function better when singing than when reading or speaking. We could certainly apply this to other scriptures, not just the Psalms; I am focused on the Psalms for this purpose though. By singing the text of the Psalms, we are (perhaps subconsciously) learning the scriptures. Some people are better at memorizing Scripture than others; yet, singing the Psalms allows us to not only worship but to also memorize the text while worshiping. It is, thus, cognitively beneficial to sing the Psalms in worship.
There Is a Theological Benefit to Singing the Psalms
Another reason to sing the Psalms in worship is that it is virtually impossible to sing bad theology when the Psalms are sung verbatim. The Psalms are part of the canon of Scripture; therefore, singing the text of the Psalms ensures that we are singing the inspired word of God rather than someone else's interpretation of the word of God. Singing the Psalms in worship then is theologically beneficial.
Singing Personalizes the Psalms
A third incentive I would give for singing the Psalms in worship is the biblical text becomes personal when it is sung. The words of the psalmists were sung by God's people in worship from centuries ago and beyond. By singing the Psalms today, the text is effectively personalized. The biblical records we have do not include the tunes but rather the text. I believe this is because the words are holy rather than the tunes. In singing the words of the Psalms, we are able to connect with saints of the past and express the very same attitudes, spirits, and emotions as they yet in our own mode through the tunes we employ. The truths of the Psalms remain; yet, they become deeply personal to us when we express and sing them in our own way. In singing the Psalms, we become uniquely connected to saints of the past yet in our own personal way.
Singing the Psalms Teaches Us How to Pray
I would also suggest that singing the Psalms teaches us how to pray. Indeed, even merely reading the Psalms accomplishes the same feat. The Psalms, in their manifold variations, are often types of prayers. An advantageous way to learn how to pray is to model our prayers after the Psalms. Whether we are praying prayers of supplication, thanksgiving, imprecation, praise, or any other form in which our prayers might manifest themselves, the book of Psalms is an excellent model. As we sing the Psalms, we are praying; we are partaking in a dialogue between ourselves (the church) and triune God. If the psalmists and the people of Israel prayed the Psalms, would it not be beneficial for us to do the same? I submit that the prayers found in the Psalms cannot be mistaken. We benefit from singing the Psalms by learning how to pray.
Singing the Psalms Expresses the Epitome of the Entire Bible
Finally, the Psalms encompass themes, stories, and really the heart of the entire Bible. The epitome, the message, and indeed the very essence of Scripture may be summed in the Psalms. Thus, when God's people sing the Psalms, the very nature of God's word is declared. The joy and frustrations of God's people are expressed, and the pure delight and satisfaction found only in God is proclaimed. Singing the Psalms then has been beneficial for the church throughout the centuries and is beneficial for the church now. In a deep connection with God's people throughout the church's history, by singing the Psalms, we are able to faithfully proclaim the story of God in worship and yet sing timeless truths in our own unique manner. It is good and right then to sing the Psalms. Let us, therefore, devotedly and unapologetically sing the Psalms with vigor, with excitement, and with joy as we worship our sovereign and saving God who loves his covenanted people.