Gibberish
It's like communicating in a second language. The mother tongue is most efficient to say important things. It's not shameful to speak English where English is the prominent language. But if a German evangelist went to India to share Jesus, the connection wouldn't be there, it would be hard to express the details needed to really share and it might be a little uncomfortable. Language can be learned, but the time it would take to fill one's mind with all the words needed to express such incredible things in a different culture could take a life time. It's a humbling thought, but for now the English will have a harder impact on the English.