'Hearts' in the Bible

Therefore judge nothing before the time, until the Lord come, who both will bring to light the hidden things of darkness, and will make manifest the counsels of the hearts: and then shall every man have praise of God.

Now their experiences serve as examples for us so that we won't set our hearts on evil as they did.

Therefore, believers, desire earnestly to prophesy [to foretell the future, to speak a new message from God to the people], and do not forbid speaking in unknown tongues.