Jesus told his disciples, " The time is coming when I will no longer speak to you in figurative languages, but I will tell you plainly about the Father" ( John 16:25). He is making a clear distinction between how he spoke to them before his death and how he will speak to them afterwards. The cause of the change lies fully in the death and resurrection.
Before Jesus' death there could be no constant fellowship between mankind and God. The punishment for sin had not yet been paid. The open communication had been broken. It is similar to one person purposely severely harming a friend and then attempting to pretend nothing happened between them. The harmed friend would find it impossible to restore the relationship without restitution for the harm.
When Jesus took our punishment upon himself, he made restitution between us and the Father. After his resurrection, he remained with his disciples for forty days and cleared up so many of their questions. They in turn wrote those answers down, so that we now possess the scriptures in which clear principles of life are given to us (2 Peter 1:3).
