We should speak of ‘submission’, rather than ‘subordination’ when talking about the relationship of God the Son to God the Father.

So argues Robert Letham, in ‘One God in Three Persons‘ (eds. Ware & Starke).

Reason: ‘subordination’ is unilateral.  One person ‘subordinates’ another, who has no choice in the matter.

‘Submission’, on the other hand, is compatible both with equality within the Godhead and order between the diffeent members.  The one who ‘submits’ is a free agent.

In terms of Christian discipleship, ‘submission’ is the epitome of godliness (Eph 5:21).  We are called to look to the interestes of others because that is the attitude of Christ himself (Phil 2:1-5).

From this,

‘it is reasonable to conclude that Christ’s life of service is revelatory of who the Son eternally is, and so of the way the three relate to one another in the unity of the indivisible Godhead. This is what God is like. Given that, there is an order—from the Father through the Son by the Holy Spirit—but not one of superior and inferior. Rather, it is an order of equals, in the identity of the indivisible Trinity, including both initiation and submission in loving exocentric union.’