Here are reasons why a fully-rounded Bible preaching/teaching ministry cannot avoid politics, and in fact must, at times, address politics to be faithful to the Lord:
1. Some people's religion is their politics, and they need to be taught to transfer their core heart-devotion from politics to Jesus Christ and the Word of God. If we love our party more than we love Jesus Christ and the Word of God, we sin. Christianity teaches a full way of looking at all of life, and we all need to change over from whatever our worldly thinking might be, to God's Word.
2. The Bible teaches us the basic nature, abilities, purpose, and responsibilities of human beings. These topics are core to social philosophy. So there is unavoidable overlap between the Bible and social philosophies.
3. The Bible also teaches us what is possible to accomplish in a fallen world, with sinful human beings. Knowing our limits is a very relevant topic to civic management.
4. The Bible teaches us the right and wrong uses of physical force. This is highly relevant to matters of the police and of the military.
5. The Bible distinguishes between the individual, the marriage, the family, the church, and the state. Each of them have rights and responsibilities, and problems erupt when one bleeds over into the other, or one swallows up the other. The Family is not the State, the State is not the Church. We need to know these things, for everything to stay in balance.
6. The Bible teaches us about the right and wrong nature and uses of authority, which has a lot of relevance to leadership. There are evils of modern-day monarchists and anarchists, The Bible enables us to avoid both.
Here, on the other hand, is what a fully-rounded Bible ministry should not do:
We should not make opinion pronouncements in the Lord's name about matters regarding which we know nothing. For example, I know almost nothing about scientific land management. I can preach a Biblical view of the physical world, and talk about the importance of God-honoring stewardship. But, unless I'm a trained conservation specialist, I'm not qualified to make pronouncements about whether diverting a certain stream will impact a certain eco-system, or whether introducing a certain plant or animal into a certain forest would be a good or bad thing. I know little about how to teach special-education students. If I am going to apply some truth of the Scripture to the field of special education, I need to educate myself first!
We should not over-emphasize social-policy messages. Some ministries are preoccupied with politics. The preachers feeds the people fire from the pulpit. There were TV messages I occasionally saw of a prominent preacher that seemed like that. They weren't edifying messages, because they didn't really teach God's Word, and so they didn't build up my relationship with the heavenly Father. Expository messages help avoid this mistake, as opposed to preaching topically. God has called us to teach the whole counsel of God, not what's on talk radio.
We should not gossip. One thing the late Francis Schaeffer used to do was write about truths and principles. He did not try to inflame the reader by attacking individuals, and I cannot think of a case where he heaved sarcasm onto someone. I am sure Francis Schaeffer, in personal conversations, could have told you exactly what he thought of various artistic, religious, or political leaders of his day! But he didn't distract you from the most important matters, by fanning the flames of philosophical or political gossip. A lot of political chatter, across the whole spectrum of opinion, often turns into a kind of gossip, and isn't particularly meaningful.
I am somewhere between pietists, who never want to talk about anything "real-world", and politics junkies, who tend to go on about politics too much. It's always a challenge to address real-world matters from God's Word.
Heavenly Father, give us grace to be remembered more for what we said that was true about You!