“Credo” comes from “cor do”, which means “I give my heart”. It’s an inspiring etymology. But I think it’s incorrect, or at best half right, a “folk etymology”, like the (false) supposition that the English posthumous derives from the Latin post humum, “after the earth”, “after burial”.
The author continues by briefly discussing other perspectives on the etymological roots of "credo," and concludes by writing:
So, if the etymology really says anything about the meaning of the word, perhaps the better reading of “credo” is not “something we give our hearts to rather than our brains” but “something (or someone) we are willing to trust or commit ourselves to”: hearts and brains and (in the older, business sense of credo) money.
Read it all.
There is something important and appealing about understanding the word "credo" as meaning "I give my heart." After all, Christian believing is not just about intellectual assent to truth claims; it's about faith. And as H. Richard Niebuhr reminds us, at its core, faith is about trust and loyalty. We do well to remember that the ultimate object of the Christian faith is not a proposition, but a Person. It's about giving our whole selves in trust and loyalty to Jesus Christ.
But placing our trust and loyalty in Jesus Christ cannot be separated from how we understand who he is. In an important sense, trusting in Jesus presupposes being shaped and influenced by what scripture and tradition say about him. Indeed, were it not for scripture and tradition, we wouldn't even know about Jesus. And so, whether we realize it or not, faith as trust in Jesus cannot be divorced from an at least implicit (if also, at times, distorted or even reluctant) trust in the Church.
Understandings of Jesus as mediated and shaped by scripture and tradition can be raised to conscious awareness and stated in propositional form. Of course, any particular individual's understanding of Jesus may be more or less adequate, or even flat-out wrong. If, for example, my understanding of Jesus can be stated as, "Jesus is a harsh, arbitrary judge who is eager to condemn me to eternal punishment in hell," then I will be unlikely to place my whole trust in him. Hence the need for the individual's understanding to be placed within the larger community of interpretation's checks and balances.
Its good sides notwithstanding, I think there are possible dangers in using the etymological explanation of "credo" as "I give my heart." Paramount is the danger of affirming a dualism between head and heart, with the heart being more important than the head. Going that route, I can imagine "credo" understood as "I give my heart" serving as a justification for subjectivism and relativism. According to such usage, the important thing is that I trust God and what I "feel" about God, etc., not that I accept the substantive doctrinal content of the creeds or what the scriptures teach. Such a perspective can lead to the view that the creeds and the scriptures mean whatever I interpret them to mean, or that they really aren't that important anyway (my subjective experience becoming a kind of rival "scripture" and "creed").
Credo without the heart can lead to a soulless rationalism divorced from the compassion of the One whom we claim to follow. On the other hand, credo without the head can lead to a gullible sentimentalism susceptible to being "tossed to and fro and blown about by every wind of doctrine, by people's trickery, [and] by their craftiness in deceitful scheming" (Ephesians 4:14). So when it comes to the meaning of "credo," we need both the heart and the head.