It is not necessary to pray to saints.
However, respecting saints is a virtue because it is virtue that respects & honors virtue.
Respecting saints can also give inspiration to people, particularly recollecting those considered to be living saints.
Respecting saints is the opposite of what many Protestants do, in vilifying saints, which is a form of envy & resentment.
It is important to be able to respect those that are more blessed than you.
Clement of Alexandria, a Church father, whilst appearing to be a zealot, was even forced to acknowledge the sanctity of Buddha.
This is truthfulness because no one can escape the truth of sanctity.
For sanctity, as I conceive it, is perfect pureness of mind, and deeds, and thoughts, and words too, and in its last degree sinlessness in dreams.
Some, too, of the Indians obey the precepts of Buddha; whom, on account of his extraordinary sanctity, they have raised to divine honours.
http://www.newadvent.org/fathers/02101.htm
