If we are to ask ourselves what formula or plan should we use to live our life to the full, I think the answer is in what Christ himself said when asked what the greatest commandment of God was.
If we believe that it is in the will of God where everything begins and ends, where what is true and good for us is contained, then we have to realize that it is in knowing and living His will or His commandment that we would be able to live our life to the full. We should be eager to put that commandment into practice.
And what was the answer of Christ to the question? "You shall love the Lord your God with all your heart, and will all your soul, and with all your mind, and with all your strength," He said. The He continued, "The second is this, You shall love your neighbor as yourself. There is no other commandment greater than these." (Mk 12,30-31)
Later on, Christ Himself summarized these commandments into a new commandment, giving us a more clear way of living the two inseparable commandments. And that is to "love one another as I (Christ) have loved you."
Christ makes Himself the standard of that love by which we have to live our life to full, since He is the very embodiment of loving God with everything, including offering His own life on the cross in obedience to the will of His Father, and of loving everyone, including those who crucified Him.
This is the basic formula to use to live our life properly. Everything has to be determined by our love for God and love for neighbor. The parameters to use in everything that we do, starting with our thoughts and intentions down to our most material activities, should be love for God and love for neighbor.
These are the determinants that should define our life and give shape to our thoughts, words and deeds. Outside of these parameters, we would be straying from the proper path.
We have to understand then that what would constitute as our true development and as our fullness of life should be the fruit of our love for God and love for the others, whoever they may be, for that is what a neighbor is–he is anyone and everyone.
We have to be wary with just doing what we like to do, even if what we do is objectively not bad since it is not a willful disobedience of God's commandments. This is because, if it not referred to the love of God and love for neighbor, it may just be an exercise of self-centeredness or selfishness.
And this is the common predicament we have around the world. People, merely relying on what they consider as personal good, just do whatever is convenient and practical to them, whatever is profitable and advantageous to them.
We have to do everything to escape from the grip of these worldly values that can only be legitimate if related to love of God and love for neighbor. We have to spread the good news that it is actually when things begin and end with God that whatever legitimate desire for success, wealth, power, etcetera, would be achieved properly.
That's why in many of our liturgical prayers, we always end with the words, "Through Christ, our Lord..." That's simply because it would only be through Christ that whatever we say or ask in our prayers is heard and acted upon by God.
In fact, in many prayers, we also express the very idea that everything begins and ends with God. A sample of this is the following favorite thanksgiving prayer of mine: Go before us, O Lord, we beseech Thee, in all our doings with Thy gracious inspiration, and further us with Thy continual help, that every prayer and work of ours may begin from Thee, and by Thee be duly ended. Through Christ our Lord. Amen.
We also have to remember that referring ourselves to God always involves referring ourselves too with others. God and neighbor cannot be separated. Our love for God would not be true if it is not carried out in our love for others. And vice-versa. Our love for neighbor would not be true if not based on our love for God.
It's this dual reference of our thoughts, words and actions that would give us the objective path for our own development and joy, a joy that would be lasting and would lead us to eternal life.