Why did God call us—according to our works or according to His purpose and grace?
God did not call believers according to their works. He called them according to His own purpose, which is completely wrapped up in His grace. That purpose is under the control of God's power, working all things according to the counsel of His own will.
Les teaches that the calling is not according to our works but according to His purposes, and those purposes are completely wrapped up in the grace of God. He points to Ephesians 1, where believers are predestined according to the purpose of Him who works all things according to the counsel of His own will. This is all under the control of God's power, whether in space, the heavens, or the earth. The end is that we should be to the praise of His glory; God leaves believers here and gives breath day after day so they might bring praise to His glory. Les also mentions Hebrews' sacrifice of praise, the work of lips, as what God is looking for.