The need is for Christians who know Scripture and theology who love God and the story of redemption, who will in winsome and fervent love take this beautiful story of redemption to their neighbors and coworkers and friends. They will be Christians who are known not simply for their keen doctrinal eye, but for their love.
Christianity has an objective definition. There are certain beliefs that must be held in order for one to be, in any meaningful sense, called a Christian. One cannot simply say they are a Christian, and then “cherry pick” their desired doctrines and proclaim, “This is Christianity.” Christianity cannot simply be what someone “feels” it means to be a Christian. The beliefs that are necessary in order for someone to be called a Christian were set forth by Christ and then hammered out in the early centuries of the church. We take the ecumenical creeds to give us the broadest definition of what it means to be Christian.
Take for instance the first two articles of the Athanasian Creed, “Whosoever will be saved, before all things it is necessary that he hold the catholic faith; Which faith except every one do keep whole and undefiled, without doubt he shall perish everlastingly.” This is saying, that unless you believe this set of doctrines (as stated by the third article: “And the catholic faith is this: That we worship one God in Trinity, and Trinity in Unity”), that which is going to follow these two articles, you can in no wise call yourself a Christian. You can be a cultic offshoot of Christianity—but you are not Christian.
Fast forward through the medieval period and the Reformation to our day, and Presbyterians are known for being thorough in their theology. We like to be precise and to make sure that we have all our boxes checked—all our t’s crossed and i’s dotted. This is a good thing. Theological precision is often the difference between damnation and eternal life (see the Athanasian creed referenced above). As John Murray said, “At the point of divergence the difference between right and wrong, between truth and falsehood, is not a chasm but a razor’s edge.” So then, this precision is a good thing, and knowing doctrine and lots of it is a good thing.