• Earliest wave (Jerusalem, 30s CE): What moved people first wasn’t “early Christian literature” (there wasn’t any yet), but the apostles’ eyewitness claim of the resurrection + their obvious transformation + the Spirit’s power at Pentecost. Acts links big influxes directly to this: Pentecost (Acts 2:41), continued witness and miracles (Acts 3–4; 4:4), and even “many priests” believing (Acts 6:7).

• How they argued in synagogues: The apostles then reasoned from the Hebrew Scriptures to show that the Messiah “had to suffer and rise” and that Jesus fits the prophecies (e.g., Acts 2:25–36; 3:18; 17:2–3; 28:23). For many Jews, Scripture was the authority, and the resurrection testimony functioned as the confirming event that made those readings plausible.

• Role of early writings: Written Gospels and most letters came a bit later and were first aimed at forming and instructing communities. In the very earliest conversions, writings were less the trigger; oral testimony + Scripture exposition + signs of the Spirit were primary. Over time, the writings preserved and propagated that same message more widely.

So is your assertion reasonable?

• It’s reasonable to say the apostles’ drastic change and resurrection witness (crowned by Pentecost) was a key engine for early Jewish belief.

• But it wasn’t instead of Scripture; rather, their testimony drove people back into the Scriptures, where the case for Jesus as Messiah was made.

• Early Christian writings reinforced and spread this later; they weren’t the main initial cause of the first Jewish conversions.

A fair summary: Spirit-empowered eyewitness testimony sparked faith; Scripture grounded it; later writings sustained and extended it.