How do you say 'praise God' in Japanese?

神様 (kami-sama) translates to "God" in Japanese, though it doesn't have a monotheistic overtone, it merely means a "God". To say "praise" in Japanese it is 賛美する (sanbisuru). So to say "Giving praise to a God" is 神様を賛美して上げっています (kami-sama wo sanbishite agettimasu). On a side note, it's probably not wise to say something like "Praise God" to anybody in any language as it can be condescending and ignorant of the other person's beliefs.