Some Christians believe there is a biblical mandate to be involved in politics because they are to be the salt of the earth. They have not well considered the meaning of the verse or the phrase as used historically.
“You are the salt of the earth. But if the salt loses its saltiness, how can it be made salty again? It is no longer good for anything, except to be thrown out and trampled underfoot.”
~ Jesus Christ, Matt. 5:13
Poor fishermen and village folk comprised Jesus’ audience. His words affirmed their worth based upon their virtue. Virtue based on the fact they were in the audience faithfully listening to him as a Prophet of God.
Salt wasn’t always for seasoning
Salt, in olden days, was a valuable commodity. Sometimes it was currency. It was far too valuable to be used as a mere seasoning to add taste to food. Perhaps you are familiar with the adage which speaks of a hard worker being “worth their salt.”
Salt was also a preservative in pre-refrigeration days. The verse does not imply that Christians are to “season” the world, its culture, or its politics. Christianity doesn’t transfer effects by mere presence or proximity.
Nor is the aim of a Christian to “preserve” the world’s culture, or politics. For what, to a true Christian, is worth preservation of either worldly culture or worldly politics? Neither impress God.
Rather, Christians derive value — to God, to one another, and to the world by virtue of their faith.
“Saltiness” comes as the result of a life lived by faith in the power of an indwelling Christ. It doesn’t come from infiltrating, influencing, and subverting politics for so-called Christian purposes. As if that could ever be a thing…