Perseverance of the Saints – Historical Interpretations before Calvin

When I read the writings of early Christians I am constantly seeing references to persevering to the end and absolutely nothing resembling this teaching. It is almost as if everything taught prior to Calvin suggests a different Gospel to the one preached by Calvinism. When I look at Scripture like Hebrews 10:29, I don't see these passages mentioned in Bible only circles, like GotQuesions.org for example where many pro perseverance scriptures are mentioned but not this one or the 80 some on other scriptures that speak opposite of this position are left out. Was the Doctrine of Perseverance of the Saints ever understood by any Christian before John Calvin? Even in the slightest?