12 “I still have many things to say to you, but you cannot bear them now. 13 When the Spirit of truth comes, he will guide you into all the truth, for he will not speak on his own authority, but whatever he hears he will speak, and he will declare to you the things that are to come. 14 He will glorify me, for he will take what is mine and declare it to you. 15 All that the Father has is mine; therefore I said that he will take what is mine and declare it to you.
--------------------
Without His doing, we would be nothing but needs and lacking, holes hopeless of being satisfied or sufficient by any true measure. We make up "measurements" to perceive a semblance of satisfaction or of hope of being intrinsically True, but the entire source of the entire satisfaction of our entire lacking is God through Christ. In Him we're made sufficient by the only true measure.
God placed His Holy Spirit with and in us. Though (1) God has always been and always will be sufficient for the Truth to be True, and (2) though Jesus was sufficient for us to be brought into a place of value, acquitted and expunged for breaking and attempting to replace Truth with our selective perception of it, we (3) also have this Counselor interceding on our behalf and navigating us as we are invited not just to know there is a Truth, not just to be restored or to observe this Truth, but to also participate in and celebrate as this spirit leads us to who this Lord is and some of what He is moving and doing to restore the kingdom of heaven through that righted relationship.
To teach only part of this begs the question - why miss out?
If God is Truth, you could stop there. That He's Truth is sufficient.
But if you know of God, why don't you ask Him about yourself?
Why overlook the Truth of what Christ accomplished for you?
Justified, we live. Christ's sacrifice is sufficient for us.
But why stop there and overlook the Holy Spirit?
This Helper is so helpful, Jesus wanted to leave so the Helper could convict and guide and counsel us.
What could be better and why would you leave any part of that out?
*The Latin word sufficere (origin of sufficient) means to put under or to meet the need of, while sufferre (origin of suffer) comes from suf(below) + fere(to bear).