Hearing the Voice of God

Is there a reliable guide to when we are really hearing the voice of God, or just a self-interested or even quite ungodly voice in the language of heaven? I think there is. Who speaks for God? When the voice of God is invoked on behalf of those who have no voice, it is time to listen. But when the name of God is used to benefit the interests of those who are speaking, it is time to be very careful.” 
― Jim Wallis, Who Speaks for God?

Do nothing out of selfish ambition or vain conceit. Rather, in humility value others above yourselves. (Phil. 2:3)

Those who do not hear from God aren't listening enough.  I hear God speaking to me through his Word, through nature, through friends and strangers alike, through my circumstances, through my work, my play, my use of money and my family.  Some of what God says is a whisper that is often hard to distinguish from my own thoughts, that is the Holy Spirit instructing and guiding my heart.  My goal is to be ever more obedient to that voice.  Some of what God says is for the benefit of others, and in these matters I need to be more discerning about the circumstances, setting and timing.  I want to speak only what is meant to build others up.  I must not put someone in an uncomfortable situation by asking a question in front of the wrong party.  I will often probe with a few questions to see if what I believe I heard from God is confirmed before I make statements- and I would be careful not to put words in God's mouth.