The clearest example that shows the meaning of baptizo is a text from the Greek poet and physician Nicander, who lived about 200 B.C. It is a recipe for making pickles and is helpful because it uses both words. Nicander says that in order to make a pickle, the vegetable should first be 'dipped' (bapto) into boiling water and then 'baptized' (baptizo) in the vinegar solution. Both verbs concern the immersing of vegetables in a solution. But the first is temporary. The second, the act of baptizing the vegetable, produces a permanent change.
Bible Study magazine, May, 1989
To immerse also means to engage wholly. How can this definition inform our understanding of Matthew 28:19?
Does in the name of really mean simply that we are to use the words Father, Son and Holy Spirit in our ritual? Or might it convey something more rich and full?
We have come to understand that, in the context of scripture, names are given and often changed in order to communicate some aspect of role or character. For example, in Genesis 17:5 we read: No longer will you be called Abram [exalted father] ; your name will be Abraham, [father of many] for I have made you a father of many nations.
Could it be that Matthew 28:19 is a definition of what it means to be a disciple in addition to (or maybe instead of??) a direct command to perform a particular ritual?
Go and make disciples. Introduce all nations to God through His Son, Jesus. Model for them and assist them in engaging fully with and being totally absorbed by the character of God, His Son, Jesus, and the Holy Spirit.
Oh. And if the ritual of immersing them in water helps in this command, that's OK, too.