The gospel basics are those essentials that we must be confident of articuluating if we are to present Christ to a world that does not know him.
The following is a very helpful exert from 'Good News is for Sharing' by Leighton Ford.
John’s Gospel was purposely written to communicate faith to non-Christians, many Christian communicators like to use its passages. It is so profound that great scholars have never completely mined its depths, yet so simple that nuggets of truth lie on the surface, as it were, for a child to pick up.
In the beginning was the Word, and the Word was with God, and the Word was God. He was with God in the beginning. Through him all things were made; without him nothing was made that has been made. (John 1:1-3)
In reply Jesus declared, "I tell you the truth, no one can see the kingdom of God unless he is born again. (John 3:3)
The Word became flesh and made his dwelling among us. We have seen his glory, the glory of the One and Only, who came from the Father, full of grace and truth. (John 1:14)
"For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life. (John 3:16)