Having a steadfast heart:
1. Means Humbling yourself in worship of the true living God
2 Kings 18:5–6
5 He trusted in the Lord, the God of Israel, so that there was none like him among all the kings of Judah after him, nor among those who were before him.
6 For he held fast to the Lord. He did not depart from following him, but kept the commandments that the Lord commanded Moses.
2 Chronicles 29:3
3 In the first year of his reign, in the first month, he opened the doors of the house of the Lord and repaired them.
2. Humbles us in Prayer
a. Prayer regarding the armies of Assyria
2 Kings 19:15–19
15 And Hezekiah prayed before the Lord and said: “O Lord, the God of Israel, enthroned above the cherubim, you are the God, you alone, of all the kingdoms of the earth; you have made heaven and earth.
16 Incline your ear, O Lord, and hear; open your eyes, O Lord, and see; and hear the words of Sennacherib, which he has sent to mock the living God.
17 Truly, O Lord, the kings of Assyria have laid waste the nations and their lands
18 and have cast their gods into the fire, for they were not gods, but the work of men’s hands, wood and stone. Therefore they were destroyed.
19 So now, O Lord our God, save us, please, from his hand, that all the kingdoms of the earth may know that you, O Lord, are God alone.”
b. Prayer regarding Hezekiah's sickness
2 Kings 20:1–7
20 In those days Hezekiah became sick and was at the point of death. And Isaiah the prophet the son of Amoz came to him and said to him, “Thus says the Lord, ‘Set your house in order, for you shall die; you shall not recover.’ ”
2 Then Hezekiah turned his face to the wall and prayed to the Lord, saying,
3 “Now, O Lord, please remember how I have walked before you in faithfulness and with a whole heart, and have done what is good in your sight.” And Hezekiah wept bitterly.
4 And before Isaiah had gone out of the middle court, the word of the Lord came to him:
5 “Turn back, and say to Hezekiah the leader of my people, Thus says the Lord, the God of David your father: I have heard your prayer; I have seen your tears. Behold, I will heal you. On the third day you shall go up to the house of the Lord,
6 and I will add fifteen years to your life. I will deliver you and this city out of the hand of the king of Assyria, and I will defend this city for my own sake and for my servant David’s sake.”
7 And Isaiah said, “Bring a cake of figs. And let them take and lay it on the boil, that he may recover.”