Excellent book, boiling down the Gospel to its essential element: Grace. We are saved by grace, not by works. Anyone who adds works as any kind of requirement or proof of salvation is distorting the Gospel of Jesus Christ. Works are for sanctification, not to be used to "check fruit". Whether or not we get into Heaven is determined by grace, alone, through faith, alone, in Christ, alone. Works determine our status with regard to service in the Kingdom to come, after Jesus comes back to Earth.
Charlie Bing explains this as clearly as it's ever been explained (next to Charles Ryrie's "So Great Salvation".