The Spirit Himself bears witness with our spirit that we are children of God.
Romans 8:16 (NKJV)
You are made complete and whole in God through Christ, and the Holy Spirit is working within you to help you discover and live this truth. According to the Apostle Paul, the revelation and reality of your sonship in Christ serve as the foundation for your wholeness and well-being.
It is good to know your identity, purpose and value are connected to the truth that you belong to God. The Apostle Paul tells us God’s Spirit Himself bears witness or speaks together with our spirit, assuring us that we are truly His children. The Greek word for “bear witness” is symmartyre, which literally means “testifying in support of someone”. This means that whenever God speaks to your spirit, He affirms the truth of your birthright in Christ (John 1:12-13).
All our spiritual problems stem from our dull hearing. Dull hearing causes a delay in spiritual growth and maturity. To grow well, we must hear the gospel again and again, allowing the Spirit to bear witness to who Christ is to us and who we are to Him. Then we can walk without contradiction in His will and word.
Learn to train your spirit to hear His Spirit, and you will live in harmony with His purpose. Even if you can't or don't understand every "specific" aspect of God's purpose, you can be confident because of His unwavering love for you. He will bring everything together for your good.