A selection of verses about Israel's second king - David:

When God rejected Saul, the first king of Israel, God told him why his successor had been chosen:

1 Samuel 13 verse 14

14 But now your kingdom will not continue. The LORD has sought for himself a man after his own heart, and the LORD has appointed him to be prince over his people, because you have not kept that which the LORD commanded you.” 

David had great faith and trust in God. When he approached Goliath, whom, naturally speaking, he had little hope of beating in a fight, he said:

1 Samuel 17 verses 45 - 47

45 Then David said to the Philistine, “You come to me with a sword, with a spear, and with a javelin; but I come to you in the name of the LORD of Armies, the God of the armies of Israel, whom you have defied. 46 Today, the LORD will deliver you into my hand. I will strike you, and take your head from off you. I will give the dead bodies of the army of the Philistines today to the birds of the sky, and to the wild animals of the earth; that all the earth may know that there is a God in Israel, 47 and that all this assembly may know that the LORD doesn’t save with sword and spear; for the battle is the LORD’s, and he will give you into our hand.” 

David said he would become king when God decided the time was right. When he had the opportunity of killing Saul and becoming king, he wouldn't take things into his own hands:

1 Samuel 26 verses 9 - 10

9 David said to Abishai, “Don’t destroy him; for who can stretch out his hand against the LORD’s anointed, and be guiltless?” 10 David said, “As the LORD lives, the LORD will strike him; or his day shall come to die; or he shall go down into battle and perish.

God made some important promises to David:

1 Chronicles 17 verses 11 - 14

11 It will happen, when your days are fulfilled that you must go to be with your fathers, that I will set up your offspring after you, who will be of your sons; and I will establish his kingdom. 12 He will build me a house, and I will establish his throne forever. 13 I will be his father, and he will be my son. I will not take my loving kindness away from him, as I took it from him that was before you; 14 but I will settle him in my house and in my kingdom forever. His throne will be established forever.” ’ ”

The offspring referred to is the Lord Jesus Christ. His mother Mary was told:

Luke 1 verses 31 - 33

31 Behold, you will conceive in your womb and give birth to a son, and shall name him ‘Jesus.’ 32 He will be great and will be called the Son of the Most High. The Lord God will give him the throne of his father David, 33 and he will reign over the house of Jacob forever. There will be no end to his Kingdom.” 

These chapters have links to this theme: