1 John 2:24

As for you, let that abide in you which ye heard from the beginning. If that which ye heard from the beginning abide in you, ye also shall abide in the Son, and in the Father.

That which ye heard from the beginning ... This is a reference to the gospel truth as proclaimed by the holy apostles of Christ, and as revealed in the sacred New Testament. Absolute and unwavering loyalty and devotion to that message, and to that alone, is here commanded; and the reward of doing so is indicated, those obeying shall abide in the Son, and in the Father.

In the Father, and in the Son ... This is a reference to the corporate body of Christ, a conception that was announced by the Lord himself in the analogy of the true vine (John 15:1-10). Thus John takes his place alongside Paul in the presentation of salvation "in Christ." A heavy emphasis upon this has been given throughout this whole series of commentaries; and, for a fuller discussion of it, see Romans 3 in my Commentary on Romans. Significantly, John here made adherence to the original gospel a prerequisite of abiding in God and in Christ. As Stott noted:

Christian theology is anchored not only to certain historical events, culminating in the saving career of Jesus, but to the authoritative apostolic witness to those events. The Christian can never weigh anchor and launch out into the deep of speculative thought.[59]

If the church of Christ in the present time would renew its vitality and increase the effectiveness of its evangelism, then let it return to a greater emphasis upon that which we have heard "from the beginning."