1. We desire our own name to be glorified instead of the name of Jesus.
This is by far the biggest issue and has many negative fruits.
We complicate this by heroizing old missionaries instead of the work God did through them. We make these people out to be super-saints, and no doubt they were not wimps. But we whitewash their history of neglecting their families and sin. These people rise to a standard no longer achievable (partially because we have no record of their foolish tweets or boneheaded blog posts). We then desire to be famous like them, and to do the great works "they" did, when really it was the Lord who did great things through them. Even when these missionary histories are written in a God-honoring way, we still read them the wrong way.
Then when our focus is on our own name being glorified, we forsake the true goal of honoring the name of Jesus and we therefore operate by own strength instead of the Holy Spirit.
With our eyes on ourselves we hope to plant a church. And build a church. And we want our church to be the biggest best church around. We aren't working to build the church, the body of Christ. Rather we want to build our church with our theology, our people we can call our own. This, we figure, brings honor to our sending churches (which is true, but it's the wrong kind of honor) and makes our supporters write bigger checks.
When we have our minds on impressing the world back home, or being super-missionaries we prefer any means by which we can in increase our numbers (of converts, or church plants, or coffee's sold to non-believers). This leads to all kinds of strange methodology and is (in my opinion) what leads to things like insider movement methodology. We'd rather have ten pseudo-Christians (I know, it's not a real thing) stuck in the slavery of Islam than one true convert who is free indeed.
Finally, this all leads to the missionary desire to be the savior instead of point people to the one who actually has the power to save.
2. We teach cultural bias and cultural theology instead of the gospel
This one is short, simple, and self-explanatory. Yet, it is very difficult to do correctly, and for the most part we're doing it wrong.
3. Neglecting the unreached for sexy people groups
See previous post for details on this.
If we really care about the lost we need to be investing as heavily in Italy, New York, and Japan as we do in Africa and the Middle East. The lost are not limited to third world countries, yet it's a lot easier to raise support to go to such places.