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.
But to what end is our knowledge? To what end do we seek to learn what the Bible teaches and what theology (systematic and Biblical) grows out of that? Obviously we are to learn and to be precise as Christians—we are often given the reminders that we are not to add to or take away from God’s Word. And, our covenant Lord says in Deuteronomy 6:6-9, “And these words that I command you today shall be on your heart. You shall teach them diligently to your children, and shall talk of them when you sit in your house, and when you walk by the way, and when you lie down, and when you rise. You shall bind them as a sign on your hand, and they shall be as frontlets between your eyes. You shall write them on the doorposts of your house and on your gates.” And we are told to, “…grow in the grace and knowledge of our Lord and Savior Jesus Christ” (emphasis added).
All our knowledge of the Scripture and theology—even in its minutia—is to be to one end. That is the end stated immediately before our passage in Deuteronomy: Hear, O Israel: The Lord our God, the Lord is one. You shall love the Lord your God with all your heart and with all your soul and with all your might. And so eloquently by Paul: And if I have prophetic powers, and understand all mysteries and all knowledge, and if I have all faith, so as to remove mountains, but have not love, I am nothing.
All our knowledge of the Bible and of doctrine—such as that of our Standards is good, and is to be sought after and longed for. However, if we heap up that knowledge and it does not produce within us love for God—not just any love, but love that is with all our heart and soul and might; and love for our neighbor—not just any love, but love that even reaches out to our enemies (Cf. Luke 10:25-37)—then we are nothing. Our knowledge is nothing.
The greatest need in our world is not just Christians who can argue minute points of theology (though, that is certainly needed when facing heretics and those who twist Scripture), but those Christians who know the minute points of theology, and it drives them. It drives them to love the great Triune Lord of Scripture. It drives them to love the Father more and the Son more and the Holy Spirit more; so much so, that they are insatiable in their desire to know Him and more about Him. Further, 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. Not some ambiguous, ephemeral, ethereal love—but a genuine, Biblical love that always brings men toward the gospel.
 Scripture quotations are from The Holy Bible, English Standard Version, copyright ©2001 by Crossway, a publishing ministry of Good News Publishers. Used by permission. All rights reserved.
 2 Peter 3:18
 Deuteronomy 6:4-5; 1 Corinthians 13:2