Really joining into Christ comes with baptism of the Spirit being given on reaching true faith in Jesus who is the Christ. Until then scriptures are the teacher as primary source of 'God's word'. Then after being given the baptism of the Holy Spirit (in other words an introduction to Him as primary teacher), and you find Him real to you, if you are willing to follow Him, He can become that primary teacher and the scriptures are there to support and encourage and confirm His lessons to you, while He forever leads and teaches. God speaks in heaven and His word is applied to His followers through Jesus and the Holy Spirit and prophets who hear. God's word was specially written over the years in scripture along with words of holy people and other relevant words. Scriptures suffice to bring you to Christ and are a source of words to which to adhere always but have weaknesses of ambiguity. These are limits which powerful direct lessons from the Holy Spirit do not have.
