We are all theologians.
Our ‘theology’ is essentially the set of controlling beliefs and thoughts that we have about God and how we are to relate to him. So, again, we are all theologians. The difference lies in whether or not our theology is intentionally (and increasingly) shaped by Scriptural teaching.
Whether or not we think about God and his will, etc., in ways that are faithful to his Word substantially determines whether or not we will relate to Him in ways that are actually pleasing to Him (cp. Col. 1:9-11). Are we the kind of worshipers he actually seeks and wants? (Jn.4:22-24).
It should come as no surprise, then, that depth of theological understanding is a necessary qualification for being a leader in the church. (e.g., Titus 1:9; cp. Jas. 3:1ff.; cp. Heb.5:11ff.)
Authentic Christian worship and experience are inescapably rooted in Biblical truth/theology (e.g, especially the teaching of Jesus in passages like Matt.5-7, John 17, etc.; and all the NT letters).
You cannot come to a deep and lasting sense of assurance of salvation and peace with God apart from an understanding and an appropriation of a section of Scripture like Rom. 3-5.
You cannot pursue authentic holiness/Christlikeness apart from understanding and applying crucial passages like Rom. 6 and Eph. 4 and Col. 3 and 1 John 3-4
You cannot rightly understand the true nature of the church, and therefore you cannot authentically carry out its true mission apart from a profound understanding of passages like Eph.2-3 and the Pastoral Epistles.
Authentic spiritual transformation is dependent on increasingly bringing our thinking (and ‘theologizing’) increasingly in line with Scripture. We are transformed, Paul says, by the renewing of our mind. And our Lord says that sanctification occurs in connection with the truth – the truth of God’s Word.
Therefore those who disparage the place of thinking, theology, Biblical truth, doctrine (‘teaching’ – cp. the Great Commission, Matt. 28:18ff.) have made a fundamental and critical mistake – and they ought to repent (i.e., change their mind). And those who presume to accept leadership roles in Christ's church have a special and particular calling to know, and live by, and minister in accordance with Biblical teaching (theology). That applies to pastors, executive pastors, college ministry pastors, 'worship leaders,' student ministry pastors, children's ministry directors, etc. And it also applies to every Christian artist, vocalist, comedian and author who puts himself or herself in the place of intentionally influencing people as to how they think about God.
As my own mentor in ministry taught me that the Second Commandment means that we are not free to 'image' (imagine) God any way we choose; we are to stick to the Image of Himself that He has given in His Word (the inscripturated Word and the Word incarnate).
Don’t tell me, “Hey, I’m no theologian…” Yes, you most certainly are. We all are. But not all are intentionally and increasingly Scriptural in their theology. Yet we all should be.