A hugely important fact in the story, but easy to gloss over, is that John believed when he saw the empty tomb and before he had fully grasped the teaching of Scripture. We often place too much importance on a person’s understanding in regards to salvation. Understanding is important, but only as it relates to belief and surrender. Complete comprehension is not necessary. What is more important is that a person recognizes their need, trusts in God for the provision of that need and the repair of the broken relationship, and that they surrender to His leadership and Lordship.
v.21 "as the Father has sent Me, I also send you."
John 3:17 For God did not send his Son into the world to condemn the world, but in order that the world might be saved through him.
John 17:18 As you sent me into the world, so I have sent them into the world.
Here in John, the Great Commission is shown to be a continuation of the Incarnation. The Church—as the Body of Christ—is given the task of continuing Christ’s mission on earth. That does not mean that the mission of the Church will, in practice, duplicate Christ’s. The means of accomplishing His task will vary and adapt but the goal will remain. The goal is the healing of the relationship between God and mankind—the salvation of humanity. Doing good to people is a part of the means of accomplishing that goal, not the primary focus. In that sense the Church will continue to help people and do good in the world, but that is not the objective. What good does it do a community if their stomachs are full but they are kept away from God, from hope? To focus exclusively on meeting physical needs in the world is to fail in the task we have been given. Incarnational ministry will do good, but not stop there.
The primary task—of believers, and of Christ—is to declare the good news and bring glory to God. Christ never helped anyone simply to alleviate physical needs. Everything He did was to declare the Kingdom of God—the world as it should be—and the good news of forgiveness under that Lordship of God and in a reconciled relationship with Him. His message and the reconciliation it declared was His focus, and in the context of His commission here (v.23), we see that is the focus of our mission.
v.28 "My Lord and my God!"
A lot of believers today think of salvation in terms of a special prayer—following an almost magical formulation. The Gospel has been distilled into a number of points that try to encapsulate the entire message in a simple repeatable form. The story itself does not preclude that sort of summary, and in places—like here in verse 28—we have a sense of that. The problem is that the current simplified versions of the Gospel are incomplete in some ways. They proclaim a product that everyone should obtain—the free gift that anyone would be stupid to forgo. What they leave off is the undeniable cost—we obtain life by giving up our “self” in the way that modernity defines it. We find not only a Savior but a Lord. We surrender ourselves as creatures before a creator. We give up self-determination, but gain the purpose for which we have been made.