You just say, “it was passed down cuz we say it was passed down!”
Seriously though, there is tremendous scriptural evidence for apostolic succession.
And from the Vatican…read here
On a logical level, does it seem appropriate at all that Jesus would pick 12 specific sinful men, fill them with the Spirit to protect them unto all Truth (Himself), send them out unto all the land to teach the Gospel, and then when John died and none were left, the Gospel would’ve been spread out enough to just take the letters from their preaching, put them and the Gospels together with the OT scrolls, wait 400 more years to establish it as inspired scripture, then wait another 1200 years to get it in print, and that’ll do 'er until the second coming? No more inspired men needed on earth, but incredibly significant for Christ Himself to work through inspired men during His own ministry? Absurd. If there’s no need for successors of apostles, and it’s all just in Scripture alone now, I wonder why Christ didn’t spend atleast as much time talking about the sole significance of a written account of God, as He did working with these 12 men to actively, physically, and orally transmit the account of God. Quite disproportionate and thin theology there.
Some arguments about this are good from a scriptural perspective, others from a logical one. I find that a combination works well…but most you’ll talk to don’t get the logic too well, and are quite biased from their protestant upbringing when it comes to their personal interpretation of scripture, so be prepared for considerable disappointment despite this solid line of defense. But all we can do is provide this truth as an alternative thought for them, and then pray the Spirit will do the rest.
p.s. gotta typo in your title line there