One thing I just realized is that when we finish up with confession and say the act of contrition the next time we sin is like lying to the Lord. Now I think that this lie is less or more severe depending on the severity of the partcular sin that was commited. It is lying because as an individual we promised not to sin but we sinned.
A firm resolution with the help of grace. That includes mortal sins. And we should intend to avoid the near occasions of sin. (Does that mean mortal and venial?)
I firmly resolve, with the help of Your grace, to sin no more and to avoid the near occasions of sin.
When I was taught the Catechism is was with the Baltimore Catechism:
Q. 770. What do you mean by a firm purpose of sinning no more?
A. By a firm purpose of sinning no more I mean a fixed resolve not only to avoid all mortal sin, but also its near occasions.
Q. 771. What do you mean by the near occasions of sin?
A. By the near occasions of sin I mean all the persons, places and things that may easily lead us into sin.
Q. 772. Why are we bound to avoid occasions of sin?
A. We are bound to avoid occasions of sin because Our Lord has said: “He who loves the danger will perish in it”; and as we are bound to avoid the loss of our souls, so we are bound to avoid the danger of their loss. The occasion is the cause of sin, and you cannot take away the evil without removing its cause.
Q. 773. Is a person who is determined to avoid the sin, but who is unwilling to give up its near occasion when it is possible to do so, rightly disposed for confession?
A. A person who is determined to avoid the sin, but who is unwilling to give up its near occasion when it is possible to do so, is not rightly disposed for confession, and he will not be absolved if he makes known to the priest the true state of his conscience.
Q. 781. Why is it well to confess also the venial sins we remember?
A. It is well to confess also the venial sins we remember: (1) Because it shows our hatred of all sin, and (2) Because it is sometimes difficult to determine just when a sin is venial and when mortal.
Q. 782. What should one do who has only venial sins to confess?
A. One who has only venial sins to confess should tell also some sin already confessed in his past life for which he knows he is truly sorry; because it is not easy to be truly sorry for slight sins and imperfections, and yet we must be sorry for the sins confessed that our confession may be valid – hence we add some past sin for which we are truly sorry to those for which we may not be sufficiently sorry.