Heart. Human heart. Seraphim of Sarov
The Holy Spirit brings into our hearts the Kingdom of God
The Scriptures say:
"In every nation he who fears God and does what is right is acceptable to Him"
People saw God and the grace of His Holy Spirit not during sleep, in dreams, or in the excitement of a disordered imagination, but truly and openly.
We have become so inattentive to the work of our salvation, that we misinterpret many other words in Holy Scripture as well, all because we do not seek the grace of God and in the pride of our minds, do not allow it to dwell in our souls. That is why we are without true enlightenment from the Lord, which He sends into the hearts of men who hunger and thirst wholeheartedly for God's righteousness or holiness.
… [T]he grace of the Holy Spirit which is granted at baptism in the name of the Father and the Son and the Holy Spirit, in spite of man's fall into sin, in spite of the darkness surrounding our soul, nevertheless shines in our hearts with the divine light (which has existed from time immemorial) of the inestimable merits of Christ. … Then, at the sinners conversion to the way of repentance, it effaces completely all trace of past sin and clothes the former sinner once more in a robe of incorruption spun from the grace of the Holy Spirit. The acquisition of this is the aim of the Christian life, which I have been explaining to your Godliness.
The Kingdom of God is now within us
And Father Seraphim, smiling pleasantly, said: "I know it myself just as well as you do, my son, but I am asking you on purpose to see whether you feel it in the same way. It is absolutely true, your Godliness! The sweetest earthly fragrance cannot be compared with the fragrance which we now feel, for we are now enveloped in the fragrance of the Holy Spirit of God. What on earth can be like it? Mark, your Godliness, you have told me that around us it is warm as in a bath-house; but look, neither on you nor on me does the snow melt, nor does it underfoot; therefore, this warmth is not in the air but in us. It is that very warmth about which the Holy Spirit in the words of prayer makes us cry to the Lord: 'Warm me with the warmth of Thy Holy Spirit!' By it the hermits of both sexes were kept warm and did not fear the winter frost, being clad, as in fur coats, in the grace-given clothing woven by the Holy Spirit. And so it must be in actual fact, for the grace of God must dwell within us, in our heart, because the Lord said: The Kingdom of God is within you (Lk. 17:21). By the Kingdom of God the Lord meant the grace of the Holy Spirit. This Kingdom of God is now within us, and the grace of the Holy Spirit shines upon us and warms us from without as well. It fills the surrounding air with many fragrant odours, sweetens our senses with heavenly delight and floods our hearts with unutterable joy. Our present state is that of which the Apostle says: The Kingdom of God is not food and drink, but righteousness and peace and joy in the Holy Spirit (Rom. 14:17). Our faith consists not in the plausible words of earthly wisdom, but in the demonstration of the Spirit and power (cp. I Cor.2:4). That is just the state that we are in now. Of this state the Lord said: There are some of those standing here who shall not taste of death till they see the Kingdom of God come in power (Mk. 9:1). See, my son, what unspeakable joy the Lord God has now granted us! This is what it means to be in the fullness of the Holy Spirit, about which St. Macarius of Egypt writes: 'I myself was in the fullness of the Holy Spirit.' With this fullness of His Holy Spirit the Lord has now filled us poor creatures to overflowing. So there is no need now, your Godliness, to ask how people come to be in the grace of the Holy Spirit. Will you remember this manifestation of God's ineffable mercy which has visited us?"