I can’t speak for other non-Catholic Christians but as far as I understand meditation is ok [b:3pefo132]if[/b:3pefo132] the self (your conscious) is still fully there. Anytime you begin to lose the self you begin to walk on thin ice. This is one of the reasons why alcohol is seen as a sin. Your conscious or free will is one of the greatest gifts given to us by God almighty. Meditation in the Catholic Church is to be fully aware of oneself and align themselves fully to God in the mind. It’s [b:3pefo132]you[/b:3pefo132] fully allowing and corresponding to God’s grace.
Hope this helps.