(Quote) Jerry-74383 said:
David's statement, while technically correct, may easily be misinterpreted.
A sin is an act. Being divorced is a state, so being divorced cannot be a sin. However, obtaining a divorce is an act -- and in some situations may be sinful for the person initiating the divorce.
It is important to keep in mind that the Church's primary concern is the spiritual welfare of all men and, ultimately, their eternal salvation. Thus, they reflect God's moral laws (the natural law), not necessarily our temporal convenience (i.e., what is easiest for us in this life).
Because of the risk of one or both spouses sinning against purity when the conjugal union is broken, either temporarily or permanently, there is a moral obligation to preserve that union whenever possible. In cases where this is not possible (which may be different than simply not desirable), especially where there is a danger to one or both spouses or the children, separations are permitted. Whenever possible, the separation should be temporary, during which time the spouses will work on correcting the problems that led to the separation and eventually reconcile. The Church does recognize that in some cases permanent separation, which may include a civil divorce for legal reasons, may be necessary; however, this option is morally valid only in extreme situations.
Obviously, when onespouse chooses to walk away from a marriage without just cause the other is not at fault for that decision: the innocent party is not morally accountable for that act.
A note on sacramental marriages:
For two baptized Christians, all valid marriages are sacramental and all sacramental marriages are valid.
When at least one spouse is not a baptized Christian, the marriage will never be sacramental (unless the person is subsequently baptized); however, it may be valid (i.e., a decree of nullity (aka an annulment) cannot be issued).
Valid non-sacramental marriages may, in some limited situations, be dissolved under the Petrine or Pauline privileges.
Valid sacramental marriages may only be dissolved if it can be proven they have not been consummated.