"Young man, if ever you would do good, you must preach the gospel and the free grace of God in Christ Jesus"
Some current buzz-words: 'integrated mission', 'holistic mission', 'holistic gospel'
At least some of the people who use the above phrases do not seem to understand the gospel at all. Yes, we should do good works. But they are not the gospel! People who never proclaim the gospel in clear words, who never call people to repentance and faith in Christ, do not have an 'integrated gospel' - they have no gospel at all!
Of course we often miss opportunities to tell others the gospel, or when we attempt to take such opportunities, we fail to discharge our duty as faithfully as we should have done. I'll certainly own up to these failings myself. But the error of people who believe and preach the 'social gospel' is far worse than this, for they turn a fault into a virtue. They make remaining permanently silent about what happened on the cross a strategy to embrace instead of a fault to repent of. The gospel becomes a program of social action instead of what Scripture declares it to be, which is:
In essence, THAT is the gospel, and taking it into all the world means verbally proclaiming those truths. It is a totally cross-cultural message, it applies in every place and time, and whilst there is scope for contextualisation in the way you present the message, if you use the 'contextualisation' argument to justify silence, then you are not being a missionary of Christ, you are being disobedient to God's word. Paul believed in being all things to all men that he might win some, but he never used that as an excuse for changing the core message above, or for remaining silent about the core message.