Aside from being a fun slogan that I enjoy employing from time to time, I am struck by the near constant debate concerning the issue of Christianity and politics, especially since the election of Donald Trump. Money talks these days, and he's certainly doing a lot of talking.
Right before we begin by praising the authorities of Romans 13, we must remember that we are to "be at peace" (εἰρηνεύοντες) with all people in 12:18. I am not going to suggest that the traditional understanding of the "authorities" in Romans 13 is wrong, but I am going to suggest that Paul has contextual reasons for saying what he says in Romans 13.
Paul lays out several items of what Christians in Rome were to do:
12:19 – "Do not take vengeance for yourselves" (μὴ ἑαυτοὺς ἐκδικοῦντες)
12:19 – "God remembers and executes vengeance," not you
12:20 – "Feed your enemy and give them hospitality"
The Roman Christians likely had no choice but to pay their taxes, but they had the choice of being hospitable to their enemies. Vengeance belongs to God, and as Paul's citation of Psalm 25:22 (LXX) states similarly, "For by doing this, you will heap burning coals on his head, and the LORD will repay you for good." Any notion of human violent resistance is subverted, and God is the one who will "repay." Plus, any attempt by a tiny minority against the imperial power of Rome would surely end up failing. What are fifty people versus ten thousand trained soldiers?
Paul also believed that the "authorities" and "powers" (Rom 13:1) were going to be destroyed by God in the end (1 Cor 15:20-28). God's power in vengeance is God's alone, not ours (Rom 12:19). Therefore, be good to your enemies by feeding them and giving them drinks. The fleeting nature of empire, even in decay (as Romans 1:18-32 suggests, as a 'decline of empire' motif), so the nature of being "subordinated" to the "authorities" is expected, especially as a people following a man executed by this same empire.
Christian non-violence, then, appears to be the idea behind Paul's own commentary in ch12, and the practical outworking of Romans 13 is both a rhetorical attempt to convey the sovereignty of God over the empire, and the "fullness of the law" being "love" (Romans 13:11).
So, it seems for Paul, "taxation is theft," but Paul's cosmic idea of Christ defeat of the rulers, principalities and powers subverts the rule and reign of Caesar. The triumph of love (vv.8-11) is at the heart of Paul's ethic here. Similarly, the community that pays taxes removes any potential violence on the part of the state, and even the ethical commands of v.13 ("do not…") are predicated on the supremacy of the risen Messiah (13:14), as opposed to the early King who fades in time.
Perhaps, by paying taxes, Paul is ultimately fulfilling the rhetoric of Christ in Luke 20:22: Caesar's coin is meaningless, because Caesar is not king. The political nature of "paying taxes" was subverted because of Christ's politics: Caesar has no currency in the Kingdom.
Similarly, Luke 23:2 seems to suggest that Jesus did not favor taxation (same word for "taxes" and tribute as in Romans 13). This is joined with the idea of Christ being "King." The difference between Paul and Jesus in this event was Paul had to fulfill the Great Commission, and if they did not pay taxes, perhaps they would be exterminated.
Is taxation theft? For Paul, probably. Is it a necessary reality in a world governed by Powers? For Paul, probably.
Just my two cents.