All good theologians have strong opinions about music, for theology is very musical in itself.  Whether you're caught-up in Irenaeus' theology of 'recapitulation', transported by the poetry of Efrem the Syrian, or simply soaked in the Psalms.  You see, there are no two ways about it: meditating on the good news of the gospel should make us sing.  The melody line of the gospel of a harmonious Triune God strikes deep resonances in our hearts.  We're used to dumb and monochrome idols, but the living God awakes our hearts, turning the volume to eleven and shaking the walls.

Handel's Messiah is perhaps the most famous example of theological music.  It dances around the scriptures retelling their central story of the Messiah; from Isaiah's prophecy of the Son to be born to a virgin, to the nations raging against the Lord and his Christ in Psalm 2 , to Job's declaration that his own eyes will see his Redeemer standing on the earth at the last day.  It is stirring stuff and the music is far from incidental.

Handel's Messiah: Hallelujah, etc.

Karl Barth, whose style of writing is often described as being musical, once wrote, '...whether the angels play only Bach in praising God I am not quite sure; I am sure, however, that en famille they play Mozart and that then also God the Lord is especially delighted to listen to them.'

You may not be convinced by Barth's musical taste but, he has a point.  Martin Luther makes a similar one, though he is—as usual—rather more pointed.  Having written that music is a gift of God, he concludes,

A person who gives this some thought and yet does not regard music as a marvellous creation of God, must be a clodhopper indeed and does not deserve to be called a human being; he should be permitted to hear nothing but the braying of asses and the grunting of hogs.

So let your theology be musical.  While theology might normally be regarded as dry, dull and unrelational, those of us who have experienced the all-singing all-dancing love of the living God know that it is music to our ears.  In your evangelism, preaching, and sharing don't subject people to braying and grunting–  sing out the gospel of Christ in all its beauty, and see how hearts respond.