English has the equivalent, God willing. It actually impacts our grammar.

This is why we use going to for the future for plans and intention, rather than will. Because will is stronger and also denotes a promise.

Thus, it is common in English today - even if 99% certain of plans to use going to, rather than will. Because will is seen to be tempting God/fate into action.

"I will get a promotion" seems to tempt the universe to intervene. Historically, we would add "God willing" to that phrase. By using going to, you can avoid having to say God willing.

Mind you, the use of inshallah is not consistently applied in the Muslim world. Turks tend to overuse it compared to Arabs, sometimes in ways it seems amusing. You can even have then say things like " I will call my friend, inshallah". Also Israelis have adopted the term also, but not other Jews. I use it when I am talking to my Muslim friends, but not outside that context. I probably say God willing 3-4 times a year, it has dropped mostly from use in English.