God helping those who cannot help themselves and God helping those who help themselves are NOT mutually exclusive options.

And the real point of the statement is two-fold. One, there are those who could help themselves but choose not to, and two, that God indeed responds to us as much as we respond to God.

Knock, and the door will be opened ≠ Sit back, wait, don't do anything, and the door will be opened.

This entire section teaching from Jesus is about being proactive, AND that God is responsive.

Where are God's hands? In your hands. Where is God's voice? In your voice. Be the instrument God needs.