What scripture says is that those who are perishing consider the gospel foolishness, and those who are being saved consider it the power of God. When someone begins to understand the gospel, they stop their movement downward into the murky waters that descend into complete destruction and begin to ascend towards the clear waters of salvation. You can be falling at any depth within the toxic disintegrating sludge of destruction when you start to reverse course and move toward the light coming from above through the clear waters of salvation. At that point, you become one who is "being saved". Being saved is not the same as fully saved. "Being saved" is "being in the process of becoming saved."
The difference between those who are sinking and perishing and those who are moving away from destruction toward the light, is that the sinking/perishing do not believe God loves them, but those aspiring upward and Godward have begun to recognise the love of God for sinners demonstrated in the life, death and resurrection of Jesus Christ. Why are some of those perishing changing their minds about God, but others who are perishing are not? Those who change began to honestly assess their situation and realise it is dysfunctional and they begin to turn from that darkness in disgust. That shift of focus away from the dark depths below is automatically a refocus towards the lighter waters above, and that looks more attractive and hopeful than the slimy brackish hopeless darkness into which they had been descending.