Divorce is not legal under the Family Code of the Philippines in the constitution. It is the only country in the world that does not allow divorce. The Philippine Constitution offers legal separation and annulment as alternatives to divorce.
Legal separation is only granted if physical abuse, drug abuse or alcoholism become marital issues. Legal separation can only end marital duties but the couple is still married in the eye of the law.
Filipinos who divorce in other countries but are legal residents of Philippines are still considered married under Philippine law.
However, Muslim Filipinos can obtain divorce in certain circumstances according to their religion. Where a non – Filipino is married to a Filipino citizen and a divorce is obtained abroad, the Filipino spouse can remarry under the Philippine law.
To the best of my knowledge the only places where divorce is actually illegal are the Vatican city and the Phillipines. Some cynics say that controlling men deliberately take residence in the Phillipines for that reason.
However, it is a feature of catholocism that people marry for life and future wives have been regarded more as mistresses. Strong believers in Catholicism believe divorce is a dreadful thing and shun family members who seek divorce. This was particularly so in Ireland but matters are easing up there perhaps because of Ireland's exposure to the wider world.
The Catholic ruling is that there should be no remarriage after a divorce if the other spouse still lives and the marriage has not been annulled. In other words, the marriage still exists despite separation unless it was never consummated.