It is prohibited to come near God without a Sacrifice (Leviticus 21:18).   

     In the Old Testament people bought animals to bring sacrifice to God. But in the New Testament buying sacrifice is illegal and God want us as living sacrifice to Him (Romans 12:1). 

     So in present days if you want to go near God you must present offerings of Praise, Thanks Giving, Worship, Prayer and Yourself as a Living Sacrifice to Him. Stay there and wait for Fire to come to accept this offering. 

     Yes people offer their sacrifice to God but never wait for the holy fire to came down to accept these offerings. Stay there and asked God - Let the Fire of Your Presence came on me and accept me as a Living Sacrifice. Let Your Holy Fire came on me because I want to be a Living Sacrifice.