Mr Forsaith was evidently a man of many parts having been at various times a sea captain, businessman, politician and Minister of the Gospel. As leader of the Liberal Party in 1854 he had the distinction of being Prime Minister of New Zealand for two days.

At the western end of the portico is the War Memorial Chapel with plaques listing the names of those from First Church who lost their lives in the World Wars. It serves as a reminder of the sacrifice of others and as a place of prayer and contemplation on entering or leaving the church.

The nave of the church which is 27 metres long, 21 metres wide and 15 metres high with a rail separating the chancel from the nave. The Communion Table is the centrepiece of the chancel. The front of the table has three panels, representing the Unity of the Trinity God the Father, God the Son and God the Holy Ghost. The centre panel contains the Christogram IHS, an abbreviated form of the Greek word for Jesus. In the outer panels are depicted ears of wheat, representing the bread, and bunches of grapes, representing the wine, the symbols of the broken body and blood of the crucified Jesus. The columns at either end of the Holy Table perpetuate features of the original pulpit, which was replaced by the present one.