[...] God Himself indicates this, saying, “He that hath My commandments and keepeth them, he it is that loveth Me” (Jn. 14:21).
For the true lover of God will preserve himself from everything that is repugnant to God, and hastens to fulfil everything that is pleasing to God. Wherefore he keeps His holy commandments.
From this it follows that those Christians that neglect the commandments have no love for God…. They love themselves and their own appetites, but not God or His holy Law.
A manifest sign of love for God is a heartfelt gladness in God, for we rejoice in what we love.
Likewise love of God cannot exist without joy, and whenever a man feels the sweetness of the love of God within his heart, he rejoices in God.
For so sweet a virtue as love cannot be felt without joy. As honey sweetens our throat when we taste of it, so the love of God makes our heart glad when we taste and see that the Lord is good (LXX Ps. 33:9).
Such joy in God is found in many places in Holy Scriptures, and is portrayed most of all in the holy Psalms. This joy is spiritual and heavenly, and is a foretaste of the sweetness of eternal life.
The true lover of God disdains the world and all that is in the world, and strives toward God, his most beloved. He counts honor, glory, riches, and all the comforts of this world which the sons of this age seek, as nothing.
For him only God, the uncreated and most beloved good, suffices. In Him alone he finds perfect honor, glory, riches and comfort. For him God alone is the pearl without price, for the sake of which he holds everything else as little. Such a one desires nothing in heaven or on earth besides God.
Such love is portrayed in the very words of the Psalter, “For what have I in heaven? And besides Thee what have I desired upon earth? My heart and my flesh have failed, O God of my heart, and God is my portion forever” (LXX Ps. 72:25).
He uses food, drink, clothing, and everything else only as needful, and not for sensual pleasure. From this it follows that whoever loves the world does not love God. According to the witness of the Apostle, “If any man love the world, the love of the Father is not in him” (1 Jn. 2:15).
Tikhon of Zadonsk (1724-1783; Russian Orthodox): extract @ Kandylaki from Journey to Heaven: Counsels On the Particular Duties of Every Christian by Our Father Among the Saints, Tikhon of Zadonsk, Bishop of Voronezh and Elets (Jordanville, NY: Holy Trinity Monastery, 2004) .