Rom 8:14 For those who are led by the Spirit of God are the children of God.
Then who are the children of God? It is clear that it is those led by the Spirit of God. But how can you tell if you are led by the Spirit and how are you led by the Spirit?
You can tell as you are being led by the Spirit when exhibiting the fruit of the Spirit. These are the qualities of the Spirit: love, joy, peace, patience, kindness, goodness, gentleness and self-control. These are the indicators you can look at to tell if you are in the Spirit or in the flesh.
You are led by the Spirit first by trust in Jesus to live in love. Then you put yourself in a position to be led through prayer and meditation and conforming to his will of love. Love even your enemies. Yielding this way to the Spirit shows you are a child of God and you will grow to exhibit more and more the fruit of the Spirit. This will confirm that you truly are a child of God.
Trust Jesus, give yourself to love, pray and meditate to put your spirit in conformity with the Spirit, yield to him. The fruit of the Spirit will be present. You are a child of God.