Why would the baptismal state of a spouse be relevant to whether someone can be confirmed in the Catholic Church? I am currently going through the RCIA process and am 4 weeks away from  being confirmed. I was just told by the priest that because my husband and I were married previously (neither in a Catholic Church) that I now need copies of our marriage certificates and a copy of my husbands baptismal certificate. There is no record of my husband being baptised and he is not a practicing catholic. What bearing does this have on me becoming confirmed?
The Catholic Church is asking for proof that your husband is a baptised Christian, baptism being the "gateway to the sacraments."


  Can.  849 Baptism, the gateway to the sacraments and necessary for
  salvation by actual reception or at least by desire, is validly
  conferred only by a washing of true water with the proper form of
  words. Through baptism men and women are freed from sin, are reborn as
  children of God, and, configured to Christ by an indelible character,
  are incorporated into the Church. (1)


Without proof, your husband is considered by The Catholic Church not baptised, which is a diriment impediment. Thus, your marriage is considered invalid.


  Can.  1086 §1. A marriage between two persons, one of whom has been
  baptized in the Catholic Church or received into it and has not
  defected from it by a formal act and the other of whom is not
  baptized, is invalid.
  
  §2. A person is not to be dispensed from this impediment unless the
  conditions mentioned in cann. ⇒ 1125 and ⇒ 1126 have been fulfilled.
  
  §3. If at the time the marriage was contracted one party was commonly
  held to have been baptized or the baptism was doubtful, the validity
  of the marriage must be presumed according to the norm of ⇒ can. 1060
  until it is proven with certainty that one party was baptized but the
  other was not. (2)


Your marriage can be rendered valid by simple convalidation...


  Can.  1156 §1. To convalidate a marriage which is invalid because of a
  diriment impediment, it is required that the impediment ceases or is
  dispensed and that at least the party conscious of the impediment
  renews consent. (3)


...or by radical sanation.


  Can.  1161 §1. The radical sanation of an invalid marriage is its
  convalidation without the renewal of consent, which is granted by
  competent authority and entails the dispensation from an impediment,
  if there is one, and from canonical form, if it was not observed, and
  the retroactivity of canonical effects. (4)


Unless your marriage is validated by The Catholic Church, you cannot be confirmed.


  Catholics seeking the sacrament of Confirmation must be married by the
  Church, either by a deacon or priest before receiving the sacrament of
  Confirmation (5, emphases added)


Your priest should have explained all of this to you. Here is a little more information.

Best wishes.