No, "He who knows his brother is committing a sin that is not until death, shall ask, and shall give life to him who does not commit a sin unto death. There is a sin unto death; I do not mean that anyone should ask as to that." 1 St. John 5:16 (Douay-Rheims) The sin unto death is mortal, the sin not unto death is venial. Venial is the Church's word for it, but the construct is Biblical, read St. John's first letter.