Why did David mourn for his house in his last words?

In 2 Samuel 23:5, David reflects on the state of his house, expressing deep sorrow that not all his family members were in fellowship with God. This mourning underscores the weight of spiritual responsibility that parents feel for their children and generations. David's lamentation reveals an awareness that a family's relationship with God is vital for eternal life. His concern echoes through the ages, reminding believers of the importance of leading their families toward faith in God, as spiritual legacy shapes the future of generations.