The Bible tells us first to be concerned about our own sin (Matt 7.3-5), and, when possible, to forebear others’ sins (Prov. 19.11). We can tell that we’ve exhausted our ability to forebear sin when anger or bitterness begins to grow in our hearts (Heb. 12.15).
Whenever conflict exists between believers, Matt. 18 prescribes the method for solving it. Unless you are a team leader on the field, your immediate leader with whom you should discuss your problems is your team leader. The first step is to approach your leader directly and humbly build your case for why you see a problem. If this fails to solve the problem, and other teammates see the same problem, gather some and go to your team leader directly. If the problem persists, your mission agency most likely has placed layers of leadership over your team leader, possibly including a leader over your city or country, and a leader over a wider region. Using a Matt. 18 approach, work your way up the ladder by approaching higher levels of leadership to resolve the problem.
If the problem persists, and it’s clear that field leaders are aligned and disagree with you, your appropriate course of action is to submit to their authority. If you cannot in good conscience submit to their authority, you may be working with a mission agency that differs substantially enough from your philosophy to warrant changing mission agencies. If so, leave in as gracious and kind a way as possible, avoiding burning relational bridges.
In the midst of continuing conflict, don’t forget to engage with your sending church, inviting their perspective and opinion. Be open and honest with the church about the conflict, and invite their prayer and shepherding over you.