I carefully wrote "divorced and re-married". In Catholic doctrine, a person who is divorced from a valid marriage and re-marries, is living in perptetual mortal sin, which even confession can't remove. Only separation from the second marriage, or death of the first spouse AND CONFESSION, can remove the sin. Therefore, they can't be saved while they remain in that condition. (if they die with ONE mortal sin unconfessed)
Well, then, they're totally screwed by your theology because there's no way of getting out of that condition.
Jesus said that if you look at a woman to lust after her in your heart, you've committed adultery with her already. That's no different in principle, because divorce also causes people to commit adultery.
This is what the works based religion of Catholicism will get you. Hell with no mercy from God.
FWIW, please provide Scripture verses to show where God distinguishes between mortal sin and venial sin.