Sustainable ...to keep up or keep going, as an action or process. To support the spirits, vitality, or resolution of; encourage.
For those who desire to know God and do the "will of God" it is critical that we discover ways to do that which are sustainable. I have learned over the years that guilt, fear and obligation are not sustainable processes when it comes to knowing God or doing the will of God. I have found 3 key things that are doable, repeatable, and give vitality that I think you will find helpful.
First: Know the Bible
To the degree you spend time reading, studying, meditating, and praying through the scriptures you will "understand what is right and just and fair - every good path". Proverbs 2:1-9
Second: Know Yourself
We are in a process of discovering who we are as God is in the process of working in us. Scripture tells us "it is God who works in you to will and act according to his good purpose." Phillippians 2:13
As we learn about what God has placed in us (spiritual gifts and passions) as well as understand how we are developing (background, personality, interests) we come to a better understanding of how to make good decisions. God created us and likes us. We are in a lifelong process that God initiated and continues to develop.
Third: Know God
We have not been called to a religious obligation but to an organic relationship. Jesus speaks of himself as "The Vine" and us as "branches". John 15:5
Our God experience has to be alive, real, and connected to be sustainable. Guilt, fear and obligation are not healthy or sustainable responses to a meaningful relationship. Prayer is simply a process or action that describes talking to God. In order to grow a relationship you have to keep talking. Talking keeps us connected.
Simplicity: As simple as these 3 things are they represent the meaningful processes that give vitality and encourage me in my attempts to know and obey God. What do you find helpful?