Indeed, Jesus says of the hard-hearted, “They will not be convinced even if someone rises from the dead” (Luke 16:31). Luke tells of many infallible proofs Jesus presented for his resurrection, yet not everyone believed. Sheer objective proof alone is insufficient to produce belief in spiritual matters; one must also be persuaded by the Holy Spirit. And even then, the will can “resist the Holy Spirit” (Acts 7:51).
— Norman Geisler, from The Apologetics of Jesus, p. 173