Unceasing prayer means to have the mind always turned to God with great love, holding alive our hope in Him, having confidence in Him whatever we are doing and whatever happens to us. That is the attitude that the Apostle had when he wrote: ‘Who shall separate us from the love of Christ? Shall tribulation, or distress, or persecution, or famine, or nakedness, or peril? Neither death nor life nor any other creature shall be able to separate us from the love of God in Christ Jesus.’ [cf. Rom. 8:35-38]
We ought not to grieve or become irritated at anything because, by frequent vexation and irritability, we form the morally and physically very injurious habit of irritability, whilst by bearing opposition with equanimity we form the good and useful habit of enduring everything calmly and patiently.
And pray ye without ceasing in behalf of other men. For there is in them hope of repentance that they may attain to God. See, then, that they be instructed by your works, if in no other way. Be ye meek in response to their wrath, humble in opposition to their boasting: to their blasphemies return your prayers; in contrast to their error, be ye steadfast in the faith; and for their cruelty, manifest your gentleness. While we take care not to imitate their conduct, let us be found their brethren in all true kindness; and let us seek to be followers of the Lord (who ever more unjustly treated, more destitute, more condemned? ), that so no plant of the devil may be found in you, but ye may remainin all holiness and sobriety in Jesus Christ, both with respect to the flesh and spirit.
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.
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.
You ask for some way of completely eradicating irritability. The inclination to irritability is given us to use against sin, and we were never meant to use it against our fellow men. When we do, we act contrary to our true nature.
Each Christian, especially a priest, should follow in example the goodness of the Lord, that everyone should be invited to partake of the Lord's food at your table. The miser is an enemy of the Lord.