Why did Saul's sins lead to his rejection as King of Israel, but David's sins did not cost him his crown?

Why did Saul's sins lead to his rejection as King of Israel, but David's sins did not cost him his crown?

ANSWER

The simplest answer is King Saul had offered a sacrifice or a burnt offering out of disobedience and therefore lose the trust of God and main trust of his people that they are following a Man of God

While King David did not lose the trust of God and did not defile a sacred offerings, and God had look upon his contrite heart seeking forgiveness and the desire to be cleanse of his sins. Truly, King David is a Man after God's heart".King David can still lead his people in following God.

EXPLANATION

In Catholic Faith, this is in parallel to offering the Holy Sacrifice of the Mass. A priest offering Holy Sacrifice of the Mass not in accordance with the Canon of the Mass commits a sacrilege.

King Saul committed a sacrilegeous offering and it is an abomination to God, while King David committed a mortal sin against the Ten Commandment. Both of the two had acknowledged their sins and seek forgiveness, a contrite heart God will not despise.

But what is the difference why King Saul lost his crown while King David retain his crown?

In a secular world, this is commonly known as "losing moral ascendency".

How can King Saul men obey their King when he was a disobedient himself? God had given us an example that in the case of Lucifer, he lost his angelic position because of pride that lead to his disobedience.

King David committed and adultery, a mortal sin, but in the King's era, people accepted that a King can have many wives as he wish and so King David "moral ascendency" was not affected by his sins.

The Heavenly Father is rich in mercy.(Ephesians2:4)

King David committed the sin of adultery but did not disobey God's Divine Law on sacred offerings.

King Saul defiled the Temple of God thru disobedience. The Temple of God is a dwelling place for the Spirit of God. We can relate this to Adam in the Garden of Eden, before his sin of disobedience he was able to talk to God, but after his fall he lost all of God's gifts and was cast out. But God's mercy & forgiveness was given to Adam & Eve, but the status of Adam as Ruler in the Garden was lost.

"Obedience is better than sacrifice."(1Samuel15:22)

Why did Saul's sins lead to his rejection as King of Israel, but David's sins did not cost him his crown?

The question seems not so much to be that both men sinned, but in the nature of the offence committed.

David committed adultery and even murder. Saul committed something far worse in the eyes of God. He committed sorcery by taking council of a medium (witch) and thus debased the trust one should have in God.

David answered, “That will give you a chance to see for yourself just how well we can fight!”

“In that case,” Achish said, “you and your men will always be my bodyguards.”

4 The Philistines went to Shunem and set up camp. Saul called the army of Israel together, and they set up their camp in Gilboa. 5 Saul took one look at the Philistine army and started shaking with fear. 6 So he asked the Lord what to do. But the Lord would not answer, either in a dream or by a priest or a prophet. 7 Then Saul told his officers, “Find me a woman who can talk to the spirits of the dead. I’ll go to her and find out what’s going to happen.”

His servants told him, “There’s a woman at Endor who can talk to spirits of the dead.”

8 That night, Saul put on different clothing so nobody would recognize him. Then he and two of his men went to the woman, and asked, “Will you bring up the ghost of someone for us?”

9 The woman said, “Why are you trying to trick me and get me killed? You know King Saul has gotten rid of everyone who talks to the spirits of the dead!”

10 Saul replied, “I swear by the living Lord that nothing will happen to you because of this.”

11 “Who do you want me to bring up?” she asked.

“Bring up the ghost of Samuel,” he answered.

12 When the woman saw Samuel, she screamed. Then she turned to Saul and said, “You’ve tricked me! You’re the king!”

13 “Don’t be afraid,” Saul replied. “Just tell me what you see.”

She answered, “I see a spirit rising up out of the ground.”

14 “What does it look like?”

“It looks like an old man wearing a robe.”

Saul knew it was Samuel, so he bowed down low.

15 “Why are you bothering me by bringing me up like this?” Samuel asked.

“I’m terribly worried,” Saul answered. “The Philistines are about to attack me. God has turned his back on me and won’t answer any more by prophets or by dreams. What should I do?”

16 Samuel said:

If the Lord has turned away from you and is now your enemy, don’t ask me what to do. 17 I’ve already told you: The Lord has sworn to take the kingdom from you and give it to David. And that’s just what he’s doing! 18 When the Lord was angry with the Amalekites, he told you to destroy them, but you didn’t do it. That’s why the Lord is doing this to you. 19 Tomorrow the Lord will let the Philistines defeat Israel’s army, then you and your sons will join me down here in the world of the dead.

20 At once, Saul collapsed and lay stretched out on the floor, terrified at what Samuel had said. He was weak because he had not eaten anything since the day before. - 1 Samuel 28

Saul was rejected as king, but remained king until he died.

The book of 2 Samuel begins with David hearing the news that his best friend and God’s anointed king have been slaughtered by the Philistines. Stunned, David is also met with news from an Amalekite (a descendant of Esau, son of Isaac the Patriarch) that the man killed Saul, taking his crown and armband for David. Expecting a reward, instead the soldier receives an execution with David asking, “Why weren’t you afraid to lift your hand to destroy the Lord’s anointed?” (v. 2 Samuel 1:14). If David was unwilling to hurt God’s anointed, why would anyone think that he would be alright with King Saul’s assassination?

David thereafter offers a memorial to Saul and Jonathan. For Saul, he sings of him being a mighty warrior; for Jonathan, he sings of him being a faithful brother. One might expect David to be jubilant about Saul’s death, but David truly never wanted Saul dead. Scholars have long noted that David’s hopes for his enemies was for them either to be removed or to repent. In Saul’s case, he definitely wished for the latter.

The kingship of David described in 2 Samuel 2 is just as exciting and dramatic as his period running away from King Saul. - David, King of Israel

What's interesting to me is that we may be comparing apples to oranges.
Saul (1 Samuel 10) was anointed to be a commander with a vial of oil.
David (1 Samuel 16) was anointed to be "king" with a horn of oil.
The first was permission for the people to have a leader other than a prophet.
The second was God's anointed choice for king, anointed with a holy oil and then a burnt sacrifice offered as a holy covenant. The second was a holy calling, without repentance.

The first was not God's divine will and plan.

My own opinion :
When Saul was anointed as King, there has no promise yet about his crown will be forever.
It seems God has a "rule" : If King Saul.... Then I will establish his kingdom forever.

1 Sam 13:13

You have done a foolish thing, Samuel said.
You have not kept the command the LORD your God gave you;
if you had
he would have established your kingdom over Israel for all time

So I think it's not about losing his crown (as Saul still continue to rule as a king after the story tell his first mistake), but about losing his chance to have his crown to be forever.

On the other hand,
before David take Uriah's wife in 2 Samuel 11 - God already promised David in 2 Samuel 7:12

And when your days are fulfilled and you rest with your fathers,
I will raise up your offspring after you,
who will come from your own body, and I will establish his kingdom

Because 2 Samuel 5:12

David did as the LORD had commanded him

I was in fact looking for an answer to God's election between Saul and David. Let me put my weak argument here:

1. It was God who chose Saul not Saul who put up his hand to be a King; Same way David was chosen by God. No prior qualifications to both.
2. In God's court the punishment is irrevocable. Priest Eli -Priesthood was taken, his children were dead, his death was a sad fall.All because of his sons. Saul Kingship was taken away and his death was terrible. Samuel was a great Priest cum Prophet but his sons were not better than Eli's sons. The same way David was a great King but he didn't go to war when it was time for the King to be in the battle field. He broke all commandments in that one sin. But still Samuel was not spared, David was spared
3. So ultimately we are trying to find an answer which we all know "God’s purpose according to his choice would stand, not because of works but because of him who calls"

The difference between Saul and David was that one offered insincere repentance while the other expressed true repentance. In David's case, we have Psalm 51 as a window into his heart.

It is instructive to look at other Biblical leaders who sinned, and what happened afterwards.

• Moses struck the rock in anger, and his punishment was that he would not live to enter the Promised Land. Moses accepted God's punishment and continued to serve. Though he did not enter the land, God's presence remained with him, and that was more precious to Moses than any material reward, showing his heart. See Exodus 33:

14 The Lord replied, “My Presence will go with you, and I will give you rest.”

15 Then Moses said to him, “If your Presence does not go with us, do not send us up from here. 16 How will anyone know that you are pleased with me and with your people unless you go with us? What else will distinguish me and your people from all the other people on the face of the earth?”

17 And the Lord said to Moses, “I will do the very thing you have asked, because I am pleased with you and I know you by name.”

18 Then Moses said, “Now show me your glory.”

• Hezekiah, in pride, showed the emissary of Babylon the treasury of Judah. God pronounced judgment against him and told him that he would die. Hezekiah repented, and God mercifully extended his life fifteen years, but years later, all that wealth was plundered by foreign armies.
• The last King before the Exile was Jehoiachin. Here is what Jeremiah had to say about him:

24 “As surely as I live,” declares the Lord, “even if you, Jehoiachin son of Jehoiakim king of Judah, were a signet ring on my right hand, I would still pull you off. 25 I will deliver you into the hands of those who want to kill you, those you fear—Nebuchadnezzar king of Babylon and the Babylonians.[d] 26 I will hurl you and the mother who gave you birth into another country, where neither of you was born, and there you both will die. 27 You will never come back to the land you long to return to.”

28 Is this man Jehoiachin a despised, broken pot, an object no one wants? Why will he and his children be hurled out, cast into a land they do not know? 29 O land, land, land, hear the word of the Lord! 30 This is what the Lord says: “Record this man as if childless, a man who will not prosper in his lifetime, for none of his offspring will prosper, none will sit on the throne of David or rule anymore in Judah.”

But what happened to this king? He did go into exile, but while there, he humbled himself before God and found favor in the court of the king of Babylon and his life was extended. He did have children, and though none sat on the throne, one descendant did become governor over Judah. This is what Haggai has to say about that man, Zerubbabel:

20 The word of the Lord came to Haggai a second time on the twenty-fourth day of the month: 21 “Tell Zerubbabel governor of Judah that I am going to shake the heavens and the earth. 22 I will overturn royal thrones and shatter the power of the foreign kingdoms. I will overthrow chariots and their drivers; horses and their riders will fall, each by the sword of his brother.

23 “‘On that day,’ declares the Lord Almighty, ‘I will take you, my servant Zerubbabel son of Shealtiel,’ declares the Lord, ‘and I will make you like my signet ring, for I have chosen you,’ declares the Lord Almighty.”

Numbered among his later descendants was Jesus Christ, the eternal king.

The pattern is that God's anger burns against a fallen leader and He pronounces a severe judgment, but if that leader's repentance is sincere, God walks back or delays part of the punishment. There is no guarantee that God's mercy will include retaining the title of kingship, as His purposes vary.

In Saul's case, what would true repentance have meant? Saul would have to acknowledge David as King and cede the throne willingly. That he would not do.

For a longer argument that defends the proposition that Saul's repentance was insincere, see https://www.ligonier.org/learn/devotionals/a-false-repentance/

This article refers to arguments made by Matthew Henry in his commentary, here summarized:

But Matthew Henry writes that “it is too evident that he only acts the part of a penitent, and is not one indeed.” To support his case, Henry notes, commenting on 1 Samuel 15:24-29:

1. Wrong audience. Saul makes his confession to Samuel only. He admits that he “ ‘transgressed the commandment of the Lord and [Samuel’s] words,’ ” but he asks only Samuel’s pardon, and that is not sufficient. He does not seem to grasp that Samuel was speaking for God, that his words were God’s.

2. Excuses. Saul excuses his fault, saying he feared the people and listened to them. But Henry notes that he never shrank before the people before.

3. Saving face. Saul is most interested in saving face. He asks Samuel to participate with him in a thanksgiving service and to honor him before the elders. He wants no one to know that God has rejected him as king.

The article goes on to show that by his words, Saul thought of God as Samuel's God, not his own, which is telling. He did not have a personal relationship.