What was the estate of Christ's humiliation?
The estate of Christ's humiliation was that low condition, wherein he for our sakes, emptying himself of his glory, took upon him the form of a servant, in his conception and birth, life, death, and after his death, until his resurrection. 1
Scripture proofs
The Westminster Assembly's proof texts (KJV). The bracketed numbers in the answer above mark the clause each set of references supports; expand a row to read the verses.
1 Phil. 2:6–8; Luke 1:31; 2 Cor. 8:9; Acts 2:24
Phil. 2:6 Who, being in the form of God, thought it not robbery to be equal with God:
Phil. 2:7 But made himself of no reputation, and took upon him the form of a servant, and was made in the likeness of men:
Phil. 2:8 And being found in fashion as a man, he humbled himself, and became obedient unto death, even the death of the cross.
And, behold, thou shalt conceive in thy womb, and bring forth a son, and shalt call his name JESUS.
For ye know the grace of our Lord Jesus Christ, that, though he was rich, yet for your sakes he became poor, that ye through his poverty might be rich.
Whom God hath raised up, having loosed the pains of death: because it was not possible that he should be holden of it.
This doctrine across the Standards
Where the Confession and the Westminster Shorter Catechism treat the same matter, so the question can be studied alongside its parallel statements.
In the Westminster Confession
VIII.4 This office the Lord Jesus did most willingly undertake, which, that he might discharge, he was made under …
This office the Lord Jesus did most willingly undertake, which, that he might discharge, he was made under the law, and did perfectly fulfill it; endured most grievous torments immediately in his soul, and most painful sufferings in his body; was crucified, and died; was buried, and remained under the power of death, yet saw no corruption. On the third day he arose from the dead, with the same body in which he suffered; with which also he ascended into heaven, and there sitteth at the right hand of his Father, making intercession; and shall return to judge men and angels at the end of the world.
→ VIII.4 · Of Christ the MediatorIn the Westminster Shorter Catechism
Q.27 Wherein did Christ's humiliation consist?
Christ's humiliation consisted in his being born, and that in a low condition, made under the law, undergoing the miseries of this life, the wrath of God, and the cursed death of the cross; in being buried, and continuing under the power of death for a time.
→ Open Q.27Q.28 Wherein consisteth Christ's exaltation?
Christ's exaltation consisteth in his rising again from the dead on the third day, in ascending up into heaven, in sitting at the right hand of God the Father, and in coming to judge the world at the last day.
→ Open Q.28