The devotion that Catholics have cultivated to the Sacred Heart of Jesus is fitting for several reasons.
First, when we revere the Sacred Heart we are recognizing the fullness of humanity in Christ. But we are doing more than just that: in ancient Israel, the heart was considered the seat of man’s being. In the Sacred Heart then, we are focusing our gaze upon Christ in the depths of His being.
Two other reasons have to do with the flames that are always associated with the heart. They signify the fact that the sacrifice on the cross was a spiritual holocaust, a burnt offering, even though physical flames were not present. And fire itself always symbolized the divine essence in the Old Testament. It is fitting then that the heart, as the essential core of man, be joined to the divine fire in the Incarnate God. In a way, the burning of the Sacred Heart becomes yet again a figure for both the humanity and divinity of Christ — the sacrifice and the God who consumes it.
However, there is yet one more reason devotion to the Sacred Heart is fitting and it is rooted in the Old Testament.
Two Old Testament passages connect the heart, word of God, and fire.
First, there is Psalm 39,
I said, “I will watch my ways,
lest I sin with my tongue;
I will keep a muzzle on my mouth.”
Mute and silent before the wicked,
I refrain from good things.
But my sorrow increases;
my heart smolders within me.
In my sighing a fire blazes up,
and I break into speech (vv. 2-4).
An intriguing parallel occurs in Jeremiah 20:
I say I will not mention him,
I will no longer speak in his name.
But then it is as if fire is burning in my heart,
imprisoned in my bones;
I grow weary holding back,
I cannot! (v. 9)
In both passages the desire for God is likened to a kind of fire. The metaphor is an apt one, as fire is representative of God — think of the burning bush that spoke to Moses, the consuming fire on Mt. Sinai, and the fire that devoured the sacrifice of Elijah.
In both cases, the fire is seated in the heart. The heart of the psalmist ‘smolders.’ Jeremiah feels as ‘if fire is burning in my heart.’ Desire for God is something that takes hold at the center of our being. It is not peripheral. It is not some mental itch or a passing passion.
In both the psalm and Jeremiah the speakers attempt to repress the fire. Both fail to do so. Here, the analogy of fire serves to explain why: just as fire cannot be contained but spreads and rises upwards, so also the desire for God overtakes both men.
And it does so in a most specific way: it issues forth in words addressed to God. Because these words are also recorded in the Bible they are Scripture — the word of God.
The psalmist had tried to ‘muzzle’ his mouth. Instead, his cry of anguish turns into a prayer. Jeremiah had also attempted to refrain from mentioning the name of God. But the fire in his heart spurs him to sing a song of praise to God. In both cases, the burning desire for God issues forth in words of prayer addressed to God.
The experience of the psalmist and Jeremiah point to a twofold way in which devotion to the Sacred Heart is fitting.
First, as perfect man, Christ experiences the desire for God more fully and expresses it more perfectly than any other. He shows us the way to stoke the fire of our heart so that it might rise up in sacrificial prayer.
Christ is not only an exemplar but also the cause, hence the second reason. His Sacred Heart — His Incarnation and sacrifice on our behalf — is what ought to light the fire of divine love in our hearts and fan the flames into prayer.
Heart of Jesus burning with love for us, inflame our hearts with love of thee!