One caution first: please, let us resolve to avoid any misunderstanding that would wrongly cause us to think that keeping moral standards or doing good works is what brings God's love to us or gives us our reward with Him. Those who love God do good because it enhances their enjoyment of the love God has already given them, and because it pleases Him. But it is certainly true that if you refuse to do good or live a life of integrity, you will spoil and trample your enjoyment of God. You can't enjoy a relationship with any other human being if you are constantly disappointing that person and treating him or her with contempt. Why should we think it is any different with God?
We are accepted by God completely freely, by believing and trusting in Christ's bearing of our sin and suffering judgment for us. We become fully and completely His children through this, before we ever do a single good work beyond believing. But even though you already have that relationship if you're a Christian, you can certainly deprive yourself of all the joy of it by living a life that disdains God's moral character and ignores His words. Therefore Keller is exactly right in saying that to "enjoy a good life... you must live a good life[.]" (emphasis added)
Whoever of you loves life
keep your tongue from evil
Turn from evil and do good;