I mean, there's a fundamental asymmetry in that relationship of creator and creature that can never really be mutual in the way a relationship between two people can. But part of what Christ modelled for us is not exploiting that asymmetry.
It might be helpful to read the edited bit I added into that last post, because I was having difficulty articulating what I meant.
But I would say that in his human life, Jesus modelled aspects of mutual submission, but that as God, the whole concept really just is kind of a category error.
He was God while on earth, though, correct? And He practiced mutual submission, despite being Master, Lord, Christ?
If you say He modeled aspects of mutual submission, then mutual submission is a mindset that can be shown by even the highest authority, to those of the lowest status.
Can you show the same type of self-sacrificing love to your child, though there is an inherent power balance? I would say yes.
Doesn't Galatians 5 describe mutual submission, just in slightly different terms?
Galatians 5:13
13 For you, brethren, have been called to liberty; only do not use liberty as an opportunity for the flesh, but through love serve one another. (NKJV)
Jesus came to serve, by His own words:
Mark 10:42-45
42 But Jesus called them to Himself and said to them, “You know that those who are considered rulers over the Gentiles lord it over them, and their great ones exercise authority over them. 43 Yet it shall not be so among you; but whoever desires to become great among you shall be your servant. 44 And whoever of you desires to be first shall be slave of all. 45 For even the Son of Man did not come to be served, but to serve, and to give His life a ransom for many.” (NKJV)
I would say that is mutual submission. It is serving one another in love, with the highest possible authority, exceeding all others, as the example.
He says let that mind be in you...
Philippians 2:1-8
1 Therefore if there is any consolation in Christ, if any comfort of love, if any fellowship of the Spirit, if any affection and mercy, 2 fulfill my joy by being like-minded, having the same love, being of one accord, of one mind. 3 Let nothing be done through selfish ambition or conceit, but in lowliness of mind let each esteem others better than himself. 4 Let each of you look out not only for his own interests, but also for the interests of others.
5 Let this mind be in you which was also in Christ Jesus, 6 who, being in the form of God, did not consider it robbery to be equal with God, 7 but made Himself of no reputation, taking the form of a bondservant, and coming in the likeness of men. 8 And being found in appearance as a man, He humbled Himself and became obedient to the point of death, even the death of the cross. (NKJV)