Answer: Water. Explanation: Water can be in the form of a liquid, solid (ice), and/or a gas (water vapor) which is represented by "three lives". As a liquid, it is used to bathe, as a gas it creates clouds that float in the sky, and as a solid (ice), it can split rocks or create glaciers that scour the earth as they move downhill.
Three lives have I. Gentle enough to soothe the skin, Light enough to caress the sky, Hard enough to crack rocks. What am I?