The essence of sound theology is knowing who God is and knowing who you are.
R.C. Sproul

We can only know God from His Word in the Bible.
Not from public opinion. Not from self-help books. The only person we should access to know God is God Himself, which He has revealed in His Word.

We can only know ourselves from our Creator, GOD.
Not from psychologists, psychiatrists, or once again, self-help books. The only person who knows about a creation is the Creator. God tells us all about ourselves in the Bible. How we were made, how we are supposed to live, what is our destiny.

Until, and only until, we know who we are: sinners in need of a Savior, we will always be lost.

For I know the plans I have for you,” declares the Lord, “plans to prosper you and not to harm you, plans to give you hope and a future. Jeremiah 29:11
The Holy Bible : New International Version. Grand Rapids : Zondervan, 1996, c1984, S. Je 29:11-12

(Jesus said, )"All that the Father gives me will come to me, and whoever comes to me I will never drive away. For my Father’s will is that everyone who looks to the Son and believes in him shall have eternal life, and I will raise him up at the last day.” John 6:37, 40.
The Holy Bible : New International Version. Grand Rapids : Zondervan, 1996, c1984, S. Jn 6:37,40