Where is the authority in the scriptures to make such a direct statement that God accepts baptism by sprinkling? By sand? I just want to see some scriptural justification, because I don't want to continue believing something that's wrong, if I'm missing something pertaining to this.
You admitted that there is no doubt all the baptisms that are recorded in the NT were via immersion. If so, where did God tell us and give us the authority to change the practice of baptism by immersion to something different? God tells us in Proverbs 14:12 and 16:25, "There is a way that seems right to a man, but its end is the way to death." Look at all of the laws He instituted for worship and sacrifice in the OT...it is very easy to say that all of those sacrifices and the way to perform them could have become ritualistic. It's exactly why He struck Nadab and Abihu dead during their consecration period, because they went outside the laws that He gave of how to perform the sacrifices. They offered unauthorized fire, and God set the tone immediately to Israel and let them know that they had better not go outside of what He had commanded them to do.
Jesus told Nicodemus in John 3:5 that he must be born again of the water and Spirit. God tells us in Revelation 22:18-19 to not add nor take away from His word. By saying you can be baptized via sand, are you not adding to God's word? The Ethiopian eunuch and Phillip were traveling through the desert when the eunuch wanted to be baptized...they found water. I honestly believe that's one of the reasons God made this earth to be composed of 75% water...so that whenever someone wants to be baptized, they can find a body of water that is just big enough to immerse him/her.