Yes, FATHER is a Scrabble word!

Letter values in Scrabble US: F 4, A 1, T 1, H 4, E 1, R 1.

Is it a valid word?

FATHER is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a male parent (also used as a term of address to your father)
the founder of a family
`Father' is a term of address for priests in some churches (especially the Roman Catholic Church or the Orthodox Catholic Church); `Padre' is frequently used in the military
(Christianity) any of about 70 theologians in the period from the 2nd to the 7th century whose writing established and confirmed official church doctrine; in the Roman Catholic Church some were later declared saints and became Doctor of the Church; the best known Latin Church Fathers are Ambrose, Augustine, Gregory the Great, and Jerome; those who wrote in Greek include Athanasius, Basil, Gregory Nazianzen, and John Chrysostom
a person who holds an important or distinguished position in some organization
God when considered as the first person in the Trinity
a person who founds or establishes some institution
the head of an organized crime family

Also: male parent, church father, father of the church, father-god, founding father, bring forth.