Monotheism barely exists

[Redbeard The Pink]

To pick rather a large nit, saints in Catholicism aren't worshipped.  Nor are angels or Mary.  Saints and Mary, particularly, are venerated.  This isn't the same as worship, which is reserved for God as expressed in the Trinity (which isn't a polytheistic concept, either).  To put it very basically, saints are never, ever prayed to, although it may appear as such to non-Catholics.  God is prayed to, saints are asked to intercede with God on behalf of the penitent.  The 'logic' behind this is that saints are especially favoured by God, and they might put in a good word (so to speak) with God for you.  Arguably the most famous prayer in Catholicism - Ave Maria - isn't a prayer to Mary, but a prayer asking Mary to pray for sinners.

It makes a weird king of sense if you were raised Catholic and said rosaries til your tongue went numb. 

Boru

It may be very catholic to apply a different label to the treatment of Jehovah and the treatment of the saints, but they're effectively the same thing, really.

If you're asking some invisible people to intercede on your behalf with some other invisible people, then it seems to me that you're praying to all the invisible people involved. If you sing songs praising those invisible people and tell stories about how awesome those invisible people are, how are those different than the worshipful songs and stories proclaimed about that one, special, central invisible person? The only way it makes sense is if you're willing to use a different word for the same thing and then believe they are two different things because the words are different.