What is the key of living right with God? How can I discern God's voice? How can I grow spiritually in Christ?
John said, "By this we know that we love the children of God, when we love God and keep His commandments. For this is the love of God, that we keep His commandments. And His commandments are not burdensome" (I John 5:2-3). The key to right living is to listen to our Maker explain how to live right. "Grace and peace be multiplied to you in the knowledge of God and of Jesus our Lord; seeing that His divine power has granted to us everything pertaining to life and godliness, through the true knowledge of Him who called us by His own glory and excellence. For by these He has granted to us His precious and magnificent promises, so that by them you may become partakers of the divine nature, having escaped the corruption that is in the world by lust" (II Peter 1:2-4).
So many people expect something mystical, but God said He speaks through His Word. God told Israel, "I will give you a new heart and put a new spirit within you; I will take the heart of stone out of your flesh and give you a heart of flesh. I will put My Spirit within you and cause you to walk in My statutes, and you will keep My judgments and do them" (Ezekiel 36:26-27). The writer of Hebrews said, "God, who at various times and in various ways spoke in time past to the fathers by the prophets, has in these last days spoken to us by His Son, whom He has appointed heir of all things, through whom also He made the worlds" (Hebrews 1:1-2). God's voice is in the Gospel.
And it is through learning the Gospel that you grow. "Therefore, laying aside all malice, all deceit, hypocrisy, envy, and all evil speaking, as newborn babes, desire the pure milk of the word, that you may grow thereby" (I Peter 2:1-2).
Then you will know that you are following God. "Now by this we know that we know Him, if we keep His commandments. He who says, "I know Him," and does not keep His commandments, is a liar, and the truth is not in him. But whoever keeps His word, truly the love of God is perfected in him. By this we know that we are in Him. He who says he abides in Him ought himself also to walk just as He walked" (I John 2:3-6).