they, like the apostles, were mere mortals, hence they are in need of guidance, that's what Jesus promised.....guidance... and He promised it until the end of time...
Wrong. Those popes were not like the apostles in the least.
The apostles were men of character and integrity.
Jesus promised the Holy Spirit and power from on high. We have Scripture and the indwelling Holy Spirit to guide, empower, and gift each individual believer.