For those living in the United States, Social Security taxes (part of the FICA taxes) are required deductions from one’s paycheck. Many other countries have very similar programs. These funds are used, in theory, to provide a financial safety net for the elderly. Once a person reaches a certain age, he or she is eligible to receive payments from Social Security. Thus, Social Security is a basic form of socialized retirement; everyone pays into the system, and everyone is paid from it. Those with less income pay much less in proportion than those with more income, and they receive a larger benefit (in proportion to their working income) than those with more, as well.
Whether or not a Christian chooses to accept Social Security payments is entirely up to him. If a person objects to the system on moral or fiscal grounds, there is no biblical mandate that he take the money. That being said, one would hope such a Christian would take a lesson from passages such as Matthew 25:14–28 and at least pass what’s offered along to some worthy cause. Whether a person takes the funds or not is simply a question of his interaction with the Holy Spirit.
Paying Social Security taxes, on the other hand, isn’t quite as flexible, though it’s certainly less popular. One of Christ’s most famous statements was in regards to taxes, in Matthew 22:15–22. The Pharisees and Herodians tried to trip up Jesus in front of a crowd by asking whether or not it was “lawful” to pay tribute money to Caesar (ESV). With this question, they pitted Jewish hatred for Roman taxation against Roman hostility against lawbreakers. Rather than give the answer many of us wish He had—“no, don’t pay taxes to Caesar”—Jesus explicitly said the taxes ought to be paid.
Other New Testament passages command believers to submit to governmental authority, even if there are limits to our obedience (Romans 13:1–7; Acts 5:28–29). In fact, in Romans, Paul explicitly says we are to pay taxes to whom we owe taxes. And, like it or not, the laws of the United States require the payment of Social Security taxes, at least for the majority of US workers.
Our responsibility to pay the Social Security tax doesn’t necessarily mean such taxes are fair or responsible or effective. Nor does it mean taxation is unfair or immoral. What it means is that, biblically speaking, Christians have an obligation to pay required Social Security taxes so long as we’re subject to the government of the United States. One’s personal opinion on whether or not the current tax system is the right way to care for the elderly is irrelevant.
Americans who object to those taxes have relatively powerful options, compared to others in the world. Voting and contact with elected officials are means to change tax laws. Since paying taxes isn’t immoral in and of itself, and we’re given clear direction to do so in the Bible, Christians ought to pay them until such time as they are no longer required.