Sayings to Ponder

I’d love to know who said:

Opportunity may knock once, but temptation bangs on the front door forever.

Some minds are like concrete, thoroughly mixed up and permanently set.

When you hit a wall, feel along it until you find a door.

Never excuse in yourself what you accuse in others. 

Don’t use a bazooka when a BB gun will do.

God promises a safe landing, not a calm passage.