What does the Bible say about the remnant of believers?

In Romans 9:27, Paul cites Isaiah, stating that although the number of the children of Israel is as the sand of the sea, only a remnant will be saved. This concept underscores God's mercy, where a select group is preserved for salvation despite widespread unbelief. In Romans 11:5, Paul reassures us that even in his own time, there remains a remnant according to the election of grace. This echoes God's faithfulness through history, ensuring that His chosen people will always be preserved and gathered, no matter the apparent state of the world around them.