Blessed be THE GOD AND FATHER of our Lord Jesus Christ

[TonyChanYT]

Berean Literal Bible James 1:

27 Pure and undefiled religion before the God and Father <τῷ Θεῷ καὶ Πατρὶ, G3588 G2316 G2532 G3962> is this: to visit orphans and widows in their tribulation; to keep oneself unstained from the world.

The article τῷ is singular. The conjunction καὶ joins two nouns but the result is singular.

The same phrase appears in 1 Peter 1:

3 Blessed be the God and Father of our Lord Jesus Christ, the One according to His great mercy having begotten us again to a living hope, through the resurrection of Jesus Christ out from the dead,

The Greek phrase refers to a singular entity.