As a Catholic, the requirement to confess sins before receiving Holy Communion is essential to approach the sacrament worthily and with a contrite heart. While there are no specific sins that must be confessed before every Communion, certain serious sins, known as mortal sins, must be confessed and absolved through the Sacrament of Reconciliation (Confession) before receiving the Eucharist. Here are twelve examples of such sins:


  1. Adultery: Engaging in sexual relations with someone other than one’s spouse.
  2. Murder: Unjustly taking the life of another person.
  3. Abortion: Deliberately terminating a pregnancy.
  4. Perjury: Giving false testimony under oath.
  5. Theft: Taking another person’s property without consent.
  6. Bearing False Witness: Spreading lies or rumors that harm someone’s reputation.
  7. Blasphemy: Speaking irreverently or contemptuously about God or sacred things.
  8. Mortal Impurity: Engaging in sexual activities outside the boundaries of marriage.
  9. Deliberate Idolatry: Giving worship or devotion to anyone or anything other than God.
  10. Willful Failure to Attend Mass on Sundays and Holy Days of Obligation: Neglecting to participate in the Eucharistic celebration without a valid reason.
  11. Hatred or Refusal to Forgive: Holding grudges or refusing to forgive others.
  12. Engaging in Serious Drug Abuse or Substance Addiction: Using drugs in a way that endangers one’s health and well-being.


Remember that it is not only the nature of the sin but also the seriousness and the degree of one’s consent that determine whether a sin is mortal. If a Catholic has committed any mortal sins, they should confess them to a priest in the Sacrament of Reconciliation before receiving Holy Communion. For venial sins (less serious sins), while it is recommended to confess them, they do not strictly require confession before receiving Communion. However, contrition and a desire for forgiveness are always encouraged before approaching the Eucharist.