2:8 Remember Jesus Christ, raised from the dead, a descendant of David; such is my gospel, 2:9 for which I suffer hardship to the point of imprisonment as a criminal, but God’s message is not imprisoned! 2:10 So I endure all things for the sake of those chosen by God, that they too may obtain salvation in Christ Jesus and its eternal glory. 2:11 This saying is trustworthy:

If we died with him, we will also live with him.

2:12 If we endure, we will also reign with him.

If we deny him, he will also deny us.

2:13 If we are unfaithful, he remains faithful, since he cannot deny himself.

Bevere writes:

Spiritual authority is promised to those who suffer like Christ. The greater hardship you endure, the greater the authority God entrusts to you. Again, you see that God sets you up for a blessing when you encounter unreasonable authority. But will you respond correctly and receive the blessing, or will you become resentful and bitter? The choice is yours. Choose the way of the overcomer, which is life! (Bevere, 177)

It is important that we look at what Paul is talking about.

If we died with him, we will also live with him.
If we endure, we will also reign with him.
If we deny him, he will also deny us.

Paul seems to be speaking more about the future reign of Christ when he returns.  James says something very similar.

James 1:12 who endures testing, because when he has proven to be genuine, he will receive the crown of life that God promised to those who love Him.

The scriptures are full of examples of the benefits of suffering in this life.  However more Spiritual authority isn’t one of these benefits.  "Spiritual authority" is a phrase that isn’t found in scripture.  In Covering Theology spiritual authority brings about more fruitfulness, divine protection, supernatural power and positional rank.  Understanding spiritual authority in this way has no foundation in scripture.

Here are the examples of the word authority used involving people.

Accept the authority of every human institution (1Pet 2:13)
Slaves accept the authority of your masters (1Pet 2:18)
Wives accept the authority of your husbands (1Pet 3:1)
Paul boasted of his authority to build up and not tear down (2Cor 13:10)
Husbands and wives have authority over each others body (1Cor 7:4)
We ought to subject ourselves to governmental authority (Rom 13:1)
Jesus gave the disciples authority over evil spirits (Mat 10:1,Luke 10:19 )

Aside from authority over Spirits none of these passages convey anything about fruitfulness or supernatural power.  Authority over evil spirits came with the name of Jesus.

Luk 9:49  John answered, "Master, we saw someone casting out demons in your name, and we tried to stop him because he is not a disciple along with us."
Luk 9:50  But Jesus said to him, "Do not stop him, for whoever is not against you is for you."

In scripture we see a distinction between three types of suffering. Peter talks about suffering as a result of your own foolishness and suffering as a result of doing good.

1Peter 2:20 "or what credit is it if you sin and are mistreated and endure it? But if you do good and suffer and so endure, this finds favour with God."

Paul talks about suffering at the hands of the super apostles.

2Co 11:19  For since you are so wise, you put up with fools gladly.
2Co 11:20  For you put up with it if someone makes slaves of you, if someone exploits you, if someone takes advantage of you, if someone behaves arrogantly toward you, if someone strikes you in the face.
2Co 11:21  (To my disgrace I must say that we were too weak for that!) But whatever anyone else dares to boast about (I am speaking foolishly), I also dare to boast about the same thing.

Paul actually chastises the Corinthians for submitting to people who take advantage of them.  There isn’t any special blessing to accepting the mistreatment of false apostles and deceitful workers.  Both Jesus and Paul layout the proper course of action when people are mistreated (Mat 18:15-17, 1Tim 5:19-20).  For more see Suffering Under Authority.

2Ti 2:13  If we are unfaithful, he remains faithful, since he cannot deny himself.

God remains faithful to us even when we are unfaithful.  We don’t simply drop off God’s radar if we live a church or the authority of a church leader.  God is not so fickle that he bases his relationship with us on the whims of another human being.

Bevere, John. Under Cover. Thomas Nelson: Nashville, 2001.