As individuals, we believers need to be asking the Holy Spirit to reveal what our sacrifices should be.  If there's something in our life needing to be sacrificed, we want to know what it is.  So we ask the Holy Spirit to reveal it to us. 

Our altar is not a physical altar in a physical body.  It's a spiritual altar in our physical body where we bring the things, both spiritual and natural, that need to be sacrificed.  This is to clean us up.  

Reverend Robert W. & Mary C. Butler