St. Isaac the Syrian (Homily 51 from his Ascetical Homilies):

If you love gentleness, be peaceful. If you are deemed worthy of peace,
you will rejoice at all times. Seek understanding, not gold. Clothe yourself
with humility, not fine linen. Gain peace, not a worldly kingdom.
No man has prudence if he is not humble, and he who lacks humility is
devoid of prudence. No man is humble if he is not peaceful, and he who is
not peaceful is not humble. And no man is peaceful without rejoicing.
In all the paths upon which men journey in this world, they will find no
peace until they draw nigh to hope in God. The heart finds no peace from
toil and from stumbling-blocks, until hope enters it, makes it peaceful, and
pours joy into it. That worshipful and all-holy mouth spoke of this when it
said, “Come unto Me, all ye that labor and are heavy laden, and I will give
you rest.” Draw nigh, He says, and hope in Me, and find rest from labor and
fear.
The Son of God endured the Cross, therefore let us sinners boldly rely on
repentance. If the form of repentance averted God’s wrath from Ahab,
surely our sincere repentance will not now be unprofitable to us. If the form
of humility turned aside divine wrath from him who was insincere, how
much more will it from us who sincerely grieve over our falls? Sorrow of
mind suffices to take the place of all bodily labor.
Saint Gregory says, “He is a temple of grace who is united with God and is
constant in his concern over His judgement.” What is concern over God’s
judgement? It is a continual seeking after His rest; mourning at all times
and a contrite meditation on account of those things that always remain
imperfect because of the wretchedness of our nature; constant sadness on
their account, which the mind retains through powerful thoughts and offers
up before God in prayer as an offering with humble compunction; and,
inasmuch as is possible and is within a man’s power, to hold solicitude for
the body in disdain. Such is the man who carries in his soul the continuous
memory of God. As Saint Basil says, “Undistracted prayer is that which
produces in the soul a distinct reflection on God. And God’s indwelling is
this: to have God established in us by [unceasing] memory of Him.” In this
manner we become temples of God. Is this not concern with a contrite
heart toward preparation for the resurrection?
To God be glory unto the ages of ages. Amen.