Do we have to use readings from the Bible for our ceremony?

We would like to have a poem read instead of one of the readings.Yes, readings from the Bible are an essential part of the marriage ceremony. If you have a special poem, you may choose to have it read at the wedding reception.
The words of Sacred Scripture are unlike any other texts we will ever hear, for they not only give us information, they are the vehicle God uses to reveal himself to us, the means by which we come to know the depth of God’s love for us and the responsibilities entailed by being Christ’s followers, members of his Body. What is more, this Word of God proclaimed in the liturgy possesses a special sacramental power to bring about in us what it proclaims. The Word of God proclaimed at Mass is ‘efficacious’ that is, it not only tells us of God and God’s will for us, it also helps us to put that will of God into practice in our own lives.
The Word of God, then calls for our listening and our response in silent reflection, as well as in word and song. Most important of all, the Word of God, which is living and active, calls each of us individually and all of us together for a response that moves beyond the liturgy itself and affects our daily lives, leading us to engage fully in the task of making Christ known to the world by all that we do and say. (U. S. Conference of Catholic Bishops)