Bible: The universe and earth are very old

2 Peter (3:5) But they deliberately forget that long ago by God's word the heavens existed and the earth was formed out of water and by water. NIV

Micah (6:2) Hear, O mountains, the LORD’s accusation; listen, you everlasting foundations of the earth. For the LORD has a case against his people; he is lodging a charge against Israel. NIV

Habakkuk (3:6) He stood, and shook the earth; he looked, and made the nations tremble. The ancient mountains crumbled and the age-old hills collapsed. His ways are eternal. NIV

Proverbs (8:22-31) The LORD brought me forth as the first of his works, before his deeds of old; I was appointed from eternity, from the beginning, before the world began. NIV

(emphasis added)

In four different chapters of the Bible, in both old and new testament, the earth is consistently described as very old.

Also see: Why the Genesis creations 'days' are long.