Did King Saul lose his salvation?

[TonyChanYT]

1 Samuel 10:

10 When they came to Gibeah, behold, a group of prophets met him, and the Spirit of God rushed upon him, and he prophesied among them.

Note that the Spirit was not in him.

1 Samuel 16:

14 Now the Spirit of the Lord departed from Saul, and a harmful spirit from the Lord tormented him.

Did King Saul lose his salvation?

It depends on how you define salvation. Saul did lose the Spirit that was given to him.

Did Saul know about resurrection and eternal life?

Saul understood salvation this way, 1 Samuel 11:

11 The next day Saul organized the troops into three divisions, and during the morning watch they invaded the camp of the Ammonites and slaughtered them, until the hottest part of the day. And the survivors were so scattered that no two of them were left together.
12 Then the people said to Samuel, “Who said that Saul should not reign over us? Bring those men here so we can kill them!”
13 But Saul ordered, “No one shall be put to death this day, for today the LORD has worked salvation in Israel.”

To him, the meaning of salvation was the physical deliverance of God. It was not spiritual eternal life.