
I think that if someone often has immoral dreams, like lustful dreams, 
or dreams where you commit acts of violence, etc. etc. it may be a sign 
that he has something sinful in his heart.  It may be the Holy Spirit's
way of allowing the sinfulness that is in us to come to light so that
we can pray about it and have it removed.  Generally, if one has a 
pure heart, and sets his mind on things that are holy, he will be holy
even when he dreams.

Dreams also can be from the Lord.  Joseph and Nebucadnezzar are two examples
of people in the Bible who received dreams from the Lord.  

Regarding out of body experiences, this is something that we have to be
careful with.  What is called an OOBE can be spiritual in nature, especially
if what one saw is the same as an experience witnessed by someone else.
Christians should certainly avoid any occult activity that would generate
an out of body experience.  Some things that might be called an OOBE
might actually be from the Lord.  Paul wrote of what might of been an OOBE.
In II Corinthians 12, he wrote of a spiritual experience of being caught
up into the third heaven.  Is an OOBE truely an OOBE?  Does one really
leave his body, or is he just seeing an image being shown to him by a
spirit, be it a demon or the Holy Spirit?  I don't think it matters
that much.  Paul could not tell.  

Be that as it may, we should be careful not to open ourselves up to Satan
to experience OOBE's.  We should not meditate and pretend we are in a 
place until our spirits apparently float there.  This is dangerous.  If
God wants to gice us what seems like an OOBE, then He can do that of His
own sovereign will.  In the Bible, most often it seems that prophets are
just taken up by God's sovereign will, and not because they are seeking
an OOBE.  John was in the Spirit praying on the Lord's day when he was
caught up in the visions he received.  Ezekial was talking with some
Jewish leaders when he was caught up into the visions of God one
time.  If God wants to take one of us up into a vision, he can do it.
People should be careful not to open themselves up to evil spirits
for the sake of a few thrills.