How should I share the gospel when it could cost me my job?
You want to honor God. You want to be faithful to the gospel, but you don't want to be foolish. You want to be responsible. You want to take the long view and not the short view. You have a responsibility to provide for your family. If you don't do that, you're worse than an infidel.
You also have a responsibility—and this is explicit both in Colossians and Ephesians—that you submit yourself to your master, whoever your boss is, whoever is over you. You don't overturn that submission. You don't run roughshod over that submission in some ill-conceived effort to fulfill the Great Commission.
I think you want to be as wise and submissive as you can be. I would just encourage you to make those kinds of opportunities sort of dependent on the Lord opening a door for you on a personal level. If you ask the Lord to give you an opportunity, I'm sure that that opportunity may arise. But I think it's irresponsible for you to overthrow your other Christian responsibilities and duties as somebody who's gainfully employed. You are taking their money and their resources with the expectation that you're going to perform according to the standard of that organization. Reserve the opportunity to communicate the gospel for those times when it's right, and the door is sensibly opened.
You should be helped along with this by realizing that the Lord again will draw His own to Him. He will find someone to communicate the gospel to them. You want to be ready and eager when that door is opened responsibly and graciously to exercise that privilege.
Lightly edited for readability, this is a transcript of John MacArthur's answer given at our 2017 National Conference. To ask Ligonier a biblical or theological question, just visit Ask.Ligonier.org or message us on Facebook or Twitter.