'Doubt' in the Bible

If word of this comes to your ears, then let this thing be looked into with care, and if there is no doubt that it is true, and such evil has been done in Israel;

When you take an oath to the Lord, do not be slow to give effect to it: for without doubt the Lord your God will make you responsible, and will put it to your account as sin

Your very life will be hanging in doubt before you, and day and night will be dark with fears, and nothing in life will be certain: