How do we explain that man (acting alone) has power to do something meriting hell, yet has no power (alone) to do something to merit heaven?
Man NEVER acts alone. “Without me you can do nothing.” (Jn 15:5) We can’t even exist alone. For God to cause us to cease existing, He would not have to do something; He would have to STOP doing something. We can’t even betray Him without His help. The one thing we can do on our own is choose to either love Him or betray Him. That choice alone is our prerogative. But it is made possible only by His power.
Fr. Vincent Serpa, O.P.