Philippians 1:27
Only, live your life in a manner worthy of the gospel of Christ, so that, whether I come and see you or am absent and hear about you, I will know that you are standing firm in one spirit, striving side by side with one mind for the faith of the gospel.

Live your life in a manner worthy of the gospel.

Mark 1:14-15
…Jesus came into Galilee, proclaiming the gospel of God, and saying "The time is fulfilled, and the kingdom of God is at hand; repent and believe in the gospel."

Acts 28:30-31
He lived there two whole years at his own expense and welcomed all who came to him, proclaiming the kingdom of God and teaching about the Lord Jesus Christ with all boldness and without hindrance.

Jesus' gospel is simply this: the kingdom of God has now, through Jesus, become available for ordinary human beings to live in. It's here. Now. You can live in it if you want to. God is present here and now. God is acting. You can revise your plans for living around this cosmic opportunity to daily experience God's favor and power.
John Ortberg

'Gospel' is the announcement that everything has changed in the coming of Jesus and it leads us to a new kind of living. It is a kingdom of God lifestyle with allegiance to a King as the ultimate restorer.
N.T. Wright

God is becoming King, and he is doing it through Jesus! And therefore, phew! God's justice, God's peace, God's world is going to be renewed.
N.T. Wright

In God’s kingdom, everything is exactly how God wants it to be.

Genesis 1:27-28
So God created mankind in his own image, in the image of God he created them; male and female he created them. God blessed them and said to them, "Be fruitful and increase in number; fill the earth and subdue it…

Through the cross, there is forgiveness of sin, restoration of God's image, and restoration of our heavenly vocation to fill and subdue the earth. 

The kingdom of God has become available to you through Jesus, so whatever happens, keep living your lives based on the reality of the greatest announcement of all time. 

Philippians 2:3-4
Do nothing from selfish ambition or conceit, but in humility regard others as better than yourselves. Let each of you look not to your own interests, but to the interest of others.

A life formed with the gospel in mind is a life dripping with humility. 

Humility: renouncing self-centered pursuits, actively regarding others in the best light possible, paying attention to the concerns and interests of others.

To live a life in a manner worthy of the gospel, we need to be people whose hearts and minds are directed away from self and toward others in the practice of attentive, humble service.

Philippians 2:5
Let the same mind be in you that was in Christ Jesus. 

Philippians 2:6-11
Who, though he was in the form of God, did not count equality with God a thing to be grasped, but emptied himself, by taking the form of a servant, being born in the likeness of men. And being found in human form, he humbled himself by becoming obedient to the point of death, even death on a cross. Therefore God has highly exalted him and bestowed on him the name that is above every name, so that at the name of Jesus every knee should bow, in heaven and on earth and under the earth, and every tongue confess that Jesus Christ is Lord, to the glory of God the Father.

Blessed be his name, he stoops, and stoops, and stoops, and when he reaches our level and becomes man, he stoops, and stoops & stoops, lower and deeper yet.
Spurgeon 

No one ever humbled himself more than Jesus. No one ever started so high, and no one ever descended so low. No one has ever given up as much as Jesus gave up.

Philippians 2:5
Let the same mind be in you that was in Christ Jesus.

How to cultivate a humble heart:

1 - Calculate One Another.

Philippians 2:3
Do nothing from selfish ambition or conceit, but in humility count others more significant than yourselves.

Count = To Calculate 

(+) Needs Of Others
(-) Your Personal Interest
= What Would Benefit Others

2 - Concern Yourself With Small Things.

Philippians 2:4
Do not merely look out for your own personal interests, but also for the interests of others.

Ministry of the Small Things (The Little Way) = Unrecognized Conquests Over Selfishness.

3 - Cooperate with God.

Philippians 2:12-13
…work out your own salvation with fear and trembling; for it is God who is at work in you, enabling you both to will and to work for his good pleasure.

Sanctification is the lifelong process of pursuing holiness—the process of God's continuing work in his beloved. 

Sanctification is working out what God has worked in. 

Grace is opposed to EARNING. Grace is not opposed to EFFORT.

Philippians 2:12-13
…work out your own salvation with fear and trembling; for it is God who is at work in you, enabling you both to will and to work for his good pleasure.

Philippians 2:14-15
Do all things without grumbling or disputing, that you may be blameless and innocent, children of God without blemish in the midst of a crooked and twisted generation, among whom you shine as lights in the world