Creeds - confessions of faith
The authors of formulated creeds tried to describe the faith in Jesus with its substantial contents, in a form as short or catchy as possible and at the same time as precisely as possible, and in a way easy to remember and to retain in order to pass it on to other people.
From the very outset, their genesis was related to, and often compelled by the need to make clear demarcations to arisen heresies and non-Christian beliefs and world views, and to clarify relevant misinterpretations and misunderstandings. Thus, formulated creeds always are documents of dogmatics and apologetics, too. The respective special detailedness of the description of certain dogmatic facts in formulated creeds reflects the conflict of the Body of Christ with the most widespread heresies and misunderstandings of their respective time of origin.
For example the Nicean Creed is primarily an answer to the heresy of Arianism spread at that time, which does not accept the divine nature of Jesus and His oneness of nature with the Father. In parallel, e.g. the Basis of Faith of the Evangelical Alliance also was a reaction to the arising "enlightenment" theology, which denies the reality and historicity of the virgin birth, the God-sonship, and the bodily resurrection of Jesus and does not believe in the physical, personal, and generally visible return of Jesus in power and glory, but heretically reinterpretes the mentioned terms by regarding them having "solely symbolic" meaning (for example by the formula of Rudolf Bultmann (1884-1976) that Jesus would have "risen" merely "into the continuous preaching (into the "kerygma") of the church").
The mere joining in or repeating of such creeds does not make anyone a Christian - this happens only if one subordinates oneself to Jesus Christ with all of one's heart and life, and enters into an intense relationship with Him. Therefore, joining in or repeating of these creeds is meaningful only as a proclamation of an already existing and lived personal faith in Jesus Christ.