For you know how, like a father with his children, we exhorted each one of you and encouraged you and charged you to walk in a manner worthy of God, who calls you into his own kingdom and glory.
1 Thessalonians 2:11-12 (ESV)
What does it mean to walk in a manner worthy of God?
It is not about trying to please God through our fleshy efforts, but rather pursuing a lifestyle empowered from within by the Holy Spirit to live a God-pleasing life. Jesus is our perfect example of one who, in the flesh, knew how to please the Father. He said:
He who sent Me is with Me. The Father has not left Me alone, for I always do those things that please Him.
John 8:29 (MEV)
The Greek word for "please" is euarestos, which meaning "well-pleasing, acceptable". It means consistently acting in accordance with the truth that is in God. Right believing lead to right living. Because Jesus saw God as His Righteous Father, all His actions were motivated by love. This is the hallmark and strength of a wonderful and intimate relationship. In the same light, the Apostle Paul exhorted the Thessalonians, like a father to his children, to follow him and walk in a manner worthy of God.
Walking worthy of God is an "identity" issue, not a "duty" issue.
If our hearts are not moved by God's deep love, we will often behave like spiritual orphans rather than true sons and daughters of our Father. Knowing that God perfectly loves you removes any fear of inadequacy and insufficiency, and this same love enables you to live well in the grace of God. Then, pleasing God is no longer an unattainable endeavour, but rather a genuine loving response to His great love.