1. The Bible is the infallible word of God.
2. God made all things, and is therefore sovereign over everything and everyone.
3. The virgin birth of Christ, that is, no man fathered him.
4. The deity of Christ (= He is the Son of God).
5. Christ died for your sins; that is, His death on the cross is the substitutionary sacrifice that turns away God's wrath and grants us forgiveness of our sins, and that we must believe this specifically for ourselves.
6. Christ saves us from sin; that is, our personal repentance from sin is based on the belief that God is working in us to make us Christlike in character.
7. Christ rose from the dead and rules His people from heaven.
8. He will one day judge all men according to their deeds.
9. Every Christian should be involved with other Christians in worship of God and fellowship.
10. One day God will raise us up to eternal life, which is the Christian hope.
IMO, if anyone doubts any of these 10 things, I would doubt that they know God's word enough to be an established Christian. There are other things also that mature Christians ought to know, which are taught in the Bible.
TD