Our practice of immersing believers is not a Baptist peculiarity. It is a biblical necessity for the following reasons. Immersion is not a mode of baptism.
Immersion is baptism.
Without immersion, baptism has not taken place. That really should settle the issue for all who wish to honor and obey the Word of God. When the Lord Jesus was baptized he went into the river Jordan. The water was not brought from the river to him. He was immersed in the water.