The Father is one with me, and I am one with the Father.
John 10:38 (CEV)
Many Christians do not have any difficulty believing that Jesus loves them, but they have trouble believing that God loves them. They feel the Father and the Son have two different minds about them. Because of this, their spiritual lives are often full of fear and insecurity. Every day they worried if they worthy of God’s love and approval, or if their salvation is in jeopardy.
When Jesus says that the Father and He are one, He is revealing to us their intimate closeness and mutual understanding of the work that the Father sent Jesus to do. In other words, both the Father and the Son loves you unconditionally and without reservation. And the finished work of the cross settled everything once and for all. Once we are in Christ, we become God's children and the Holy Spirit is sent to confirm with our inward conviction that we are truly children of God (cf. Romans 8:16).
Knowing that the Trinity is at work in our salvation, we have every help we need to enable us to believe and live right. The Christian life is not about trying to achieve perfection. Nothing is missing in you because you have already been made full with the fullness of Christ who fills all in all (cf. Ephesians 1:23). All that is needed is a continuous personal experience of your fullness in Christ through faith.
Your fullness in Christ means knowing who you are and what you have in Christ. This is the basis of finding rest in God's grace. Rest is not about achieving, but about receiving. As you receive the life and love of the Father, the Son, and the Spirit, you can truly experience the reality of perfect love in many real and tangible ways.