Plenty of Biblical evidence for the Trinity, just because the word 'trinity' isn't in there doesn't mean a thing.
Another pointless argument though, like so many others as those who have been convinced simply wont change their minds and no amount of Biblical evidence will change it.
"In the beginning was the Word, and the Word was with God, and the Word was God. 2He was with God in the beginning. 3Through him all things were made; without him nothing was made that has been made. 4In him was life, and that life was the light of all mankind. 5The light shines in the darkness, and the darkness has not overcome it."