What does the Bible say about keeping secrets?

A secret can be difficult to keep and equally difficult to share. Yet
life seems to run on secrets, from concealing birthday presents to
obscuring a difficult past to protecting the whereabouts of an
important political figure. The Bible teaches, indirectly, that
secrets can be either good or bad, but it does not clearly delineate
the right and wrong uses of secrets.

Throughout the history of Israel, political and military secrets are
mentioned without pronouncing any moral judgments for or against them
(e.g., 2 Samuel 15:35-36). However, in the story of Samson and Delilah
(Judges 16:4-22), Samson reveals the source of his strength, an act
which, based on the aftermath of his admission, was awfully stupid. It
was a secret he should have kept.

Esther's story provides a positive example of someone who kept a
secret. Her decision to hide her nationality (Esther 2:20) became an
integral part of God's plan to save His people (Esther 4:13; 7:3-6).
The same story also supports the morality of revealing a secret that,
if kept hidden, would cause great wrong or serious harm (Esther
2:21-23).

Proverbs, the central book among the "wisdom literature" of the Bible,
is the most explicit about secrets. Chapter 11 says that "a man of
understanding holds his tongue. A gossip betrays a confidence, but a
trustworthy man keeps a secret" (v. 12-13). So, keeping a secret can
be noble. But secrets kept for the wrong reason earn a person the
title of "wicked," for "a wicked man accepts a bribe in secret to
pervert the course of justice" (Proverbs 17:23), and "whoever slanders
his neighbor in secret, him will I put to silence" (Psalm 101:5).

One type of secret is always wrong: trying to hide sin. "He who
conceals his sins does not prosper, but whoever confesses and
renounces them finds mercy" (Proverbs 28:13). When it comes to our
sin, God wants full disclosure, and He grants full forgiveness (Isaiah
1:18).

Of course, there's no use trying to hide our sin from God. Nothing can
be kept from Him. He is "the God of gods . . . and a revealer of
secrets" (Daniel 2:47, NKJV). Even our "secret sins" are exposed in
His light (Psalm 90:8). "For nothing is secret that will not be
revealed, nor anything hidden that will not be known and come to
light" (Luke 8:17).

God Himself keeps some things—probably many things—hidden from us:
"The secret things belong to the LORD our God" (Deuteronomy 29:29).
Jesus asked several people to keep miracles He had done secret. For
example, Jesus healed two blind men and told them to "see that no one
knows about this" (Matthew 9:30). When Job realized the immensity of
God's knowledge, he spoke of "things too wonderful for me to know"
(Job 42:3).

We can conclude that God does not consider keeping a secret to be
sinful in and of itself. There are some things that people should know
and some things they should not. God's concern is how secrets are
used, whether to protect or to hurt.