Reformed theology approaches Mark 16:9-20 with scholarly caution. Many early manuscripts lack the Longer Ending, and textual critics note it may be a later addition. However, the Westminster standards do not pronounce definitively against it, and many Reformed communities include it. Calvin himself noted the textual issue but did not exclude the passage from Scripture.

If authentic, the passage affirms Christ's resurrection and the commission to preach the gospel. Reformed interpreters understand the 'signs' (Mark 16:17-18) as accompaniments to apostolic preaching, not as promises of universal miraculous phenomena in all believers. The passage's core message—the risen Christ commissions his disciples—aligns with Reformed eschatology and missiology regardless of its textual status.