If we want to discover what it means to believe in the Triune God, then the clear revelation of this truth that there is one God in three persons is found in the New Testament, especially but not exclusively in John’s Gospel. However significant foundations for this revelation were already laid in the Old Testament and that is particularly true of Isaiah.
Isaiah places an emphasis on the one true God who is high and exalted, incomparable and without rival (6:1-7; 40:9-26). He is the God who will not share his throne or give his glory to another (42:8). We start with the oneness of God, Isaiah’s view of worship is emphatically monotheist.
This God is the one who sends. If, John will point us to the Father who sends his Son in human flesh, Isaiah points us to Yahweh sending his servant (42:1). This servant is human, he comes to serve and to suffer so that he willingly bears God’s wrath and receives the penalty for sin that we deserve (53). He is not just a servant though, he is a judge, a ruler, a king who is just and righteous (11:1), he is Immanuel, God with us (7:14):.
More than that, there is at least the hint in the context where God declares that he will not share his glory with a rival and in the promise that the suffering servant will prosper for eternity that the servant somehow does get to share in God’s glory. Whilst God sends a deliverer, we also see that he is himself the one coming as deliverer (4:1-5). The righteous and just king is more than an earthly ruler but is described as mighty God and everlasting father, the ruler of a boundless kingdom (9:6-7). All of this at least begins to point us to one who is at the same time God and man. There is a second person in the Godhead but without any breach in the oneness of that Godhead.
Then throughout Isaiah, there is constant reference to the Spirit of God. This is primarily linked to God’s anointed or appointed king and servant. So, God’s Spirit is a spirit of righteousness, justice, wisdom and understanding (11:2). The Spirit will be “poured out from on high” (32:15; 44:3), pointing to Pentecost. The Spirit will gather God’s people (34:16). The Spirit is immeasurable and incomparable (40:13). The Spirit will rest upon the servant (42:1). God sends his spirit (48:16). The Spirit of God is on the speaker of Isaiah 61 (who we discover in the New Testament is Jesus, ushering in a year of Jubilee freedom and healing.
So, throughout Isaiah, we see the Triune, one God in three persons at work bringing judgement, preserving the remnant and ushering in renewal and restoration.
Faithroots 