Belief in God as Father, Son and Holy Spirit is at the heart of our faith. Christians believe that Jesus is God’s Son. Jesus reveals to us that God is our Father and that God is available to us through the Holy Spirit.
You won’t ever be asked if you completely understand all this. But you are asked whether you believe and trust.
This is called faith. It is a different sort of knowledge. It is the knowledge of being known and loved, and of loving in return.
The Christian faith is not a human invention.
There are signs of God’s existence and handiwork in creation for anyone to read (Acts 14.15–17). But we believe in the way we do because God has come to seek us out and has made himself known to us.