Holiness is not simply righteousness, for which the righteous are rewarded with blessedness in the Kingdom of God; rather, it is such a height of righteousness that people are so filled with the grace of God that it flows from them even upon those who associate with them. Great is their blessedness, which proceeds from their direct contemplation of the glory of God. Being filled also with love for men, which proceeds from love of God, they are responsive to men's needs, and at their entreaties they act as mediators and intercessors for them before God.
In everything we do, God looks as the aim, whether it is for Him or for some other purpose we act. So, when we wish to do something good, let us have as our aim not to please men but to please God, so as to have our eyes always fixed on Him, doing everything for Him, lest we bear the labor but lose the reward.
In answer to your question as to what constitutes a happy life, whether splendor, fame and wealth, or a quiet, peaceful, family life, I will say that I agree with the latter, but will add the following: A life lived in humility and with an irreproachable conscience brings peace, tranquility, and true happiness. But wealth, honor, glory and exalted position often serve as the cause of a multitude of sins, and such happiness is not one on which to rely.
If we want to do something but cannot, then before God, Who knows our hearts, it is as if we have done it. This is true whether the intended action is good or bad.
If we fervently desire holiness, the Holy Spirit at the outset gives the soul a full and conscious taste of God’s sweetness, so that the intellect will know exactly of what the final reward of the spiritual life consists.
But if you are fearful of becoming self-righteous from working for your own salvation, or afraid of being overcome by spiritual pride, examine yourself and observe that the person who is afraid of becoming self-righteous suffers from blindness. For he does not see how self-righteous he is.