+Matthew clearly places the perseverance on the believer.
God also ordained that He would ensure this perseverance: Phil 1:6 : ... being confident of this, that he who began a good work in you will carry it on to completion until the day of Christ Jesus
+Paul clearly places the perseverance on God, and not the believer.
The Church follows the Gospels. The Protestants follow their interpretation of +Paul.
According to +Paul's view, wickedness would have no effect on us since God is not affected by wickedness. In fact, in Phil. 1:10 he speaks of being "blameless" to the end.
Thus, the Gospels lead us to repentance. The Epistle lead us to believe that once we are "washed" in Christ's Blood we are blameless in His eyes and therefore cannot do wrong, even if we sin. Hence, repentance for the Protestant is a one-time event. Afterwards is self-righteousness to the end.
These are clearly two different religions. Only one is taught by Christ in person. The other one believes in Christ through proxy.
My sheep hear my voice, and I know them, and they follow me. I give eternal life to them. They will never perish, and no one will snatch them out of my hand. My Father, who has given them to me, is greater than all. No one is able to snatch them out of my Father's hand. (John 10:27-29 WEB)
What percentage of Christ's sheep will perservere to the end? What percentage of Christ's sheep will fall from Christ's hand?
That is decidedly NOT Paul's view since he laments doing what he does not wish to do, but that which he wishes to do, he does not. (Rom. 7:15-20) Paul says explicitly that the wickedness of sin still lives in us to an extent. Phil. 1:10 is part of Paul's prayer. Who wouldn't pray for a loved one to never sin again?
I also associate myself with Marlowe's excellent response. :)