The following quote appeared in Forum Letter, volume 46, number 5, May 2017. Forum Letter is a monthly publication of the American Lutheran Publicity Bureau.
Some modern folk evidently find Psalm 109 difficult to pray. … The sentiments contained in it, after all, seem so violent and vengeful, so greatly at odds with the sorts of feelings that one would prefer to have during prayer. …
The real problem, nonetheless, is not with the psalm, but with ourselves. We modern Christians are far too disposed to establish our personal sentiments, our own spontaneous feelings, as the standard for our prayer. Thus, if the words of a particular prayer (in this case, a psalm inspired by the Holy Spirit) express emotions and responses with which we do not ‘feel’ comfortable, we tend to think that we are being insincere in praying it. Contemporary Christians have made a virtual fetish of spontaneity in worship, and sincerity nowadays is measured by pulse rhythm. One would think that our Lord had said: ‘I have come that you may have sincere and heartfelt emotions, and have them more abundantly.’
It is a big mistake to adopt this attitude, for it places even the authority of God’s inspired Word under the tribunal of our subjective sentiments. Is it not obvious that to set up our own feelings as the measure of our worship is utterly arrogant? The proper standard for the worship of God is already established in His unchanging Word, and no one will pray as he should unless he submits his prayer entirely to the authority of the Word. Otherwise there is a real danger that our worship will express only the unredeemed sentiments of unrepentant hearts. – Patrick Henry Reardon, Christ in the Psalms (Conciliar Press, 2000), 215