The building itself is constructed of Portland stone with Bath stone dressing on the interior. Entering from the south door, the immediate impression is of spaciousness and proportion.
To the left is the elegant little baptistery which reflects the shape of the Lady Chapel.
The windows around it depict (from left to right):
John the Baptist
The words under the figures read: "He shall baptise you with the Holy Spirit.
The font came from Christ Church, West Fordington in 1932. The cover, made by parishioner Mr Rod in 1963, was given in memory of Father Colyer, Vicar from 1940 to 1957 and consists of panels of sycamore and mahogany, surmounted by a silver cross.
Above the baptistery the West window, well lit in the late afternoon and evening, dates from 1939. The subject is the Ascension of the Lord. Beneath him on the ground is Our Lady in prayer, and in the lights on either side stand the eleven apostles.
Looking eastwards, the eye is drawn to the sanctuary, and the east window. This was put in place after the 1914-18 war. It represents the Church triumphant adoring our Lord in majesty.
In the upper portion of the side lights are the heavenly hosts, below the enthroned Lord, St. Gabriel and St. Michael.
1st light left: St Anthony of Padua, Moses, St Joseph, St. George and St. Peter.
2nd left: St. Helena, King David, Isaiah. Hezekiah, St. John and Our Lady.
1st right: St. Thomas, apostle of India, St. Cecilia, patron of music, St. Agnes, Jeremiah, St. John Baptist, St Mary Magdalene.
2nd right: St. Anne, St. Nicholas, St. Methodius, St. Cyril and St. Dennis (some of the saints were Patron saints of the allied countries in the war.)
The kneeling figure in the foreground is that of St. Paul Apostle to whom the church is dedicated. The central opening, in the form of a cross, bears a scroll with the words "King of Kings".
Originally intended as a memorial to the dead of the First World War, the window was the gift of Major Groves of Westdowne Lodge in Chickerell Road. This allowed the money raised for a memorial to be spent on the magnificent reredos, and the stone cross outside. The reredos was designed by Mr G.H. Fellowes Prynne, the architect of the church.
The reredos is in triptych form. The plain oak panelling on either side, containing the names of the fallen, contrasts with the richness of the reredos itself. The carved frame was executed by wounded ex-soldiers. This is capped with a carved cornice and open cresting and the base has small panels with six shields, bearing the emblems of the passion, together with those of St. Paul, St. Peter, St. George and the Archangel Michael.
These four Saints are also depicted in the side panels of the reredos.
The central panel of mosaic depicts the Risen and Glorified Lord with two adoring angels. The inscription underneath in Latin, reads " Nunc autem Christus resurexit a mortuis primitae dormentium" - "Now is Christ risen from the dead, the first fruits of them that are asleep"
The riddel posts on either side of the reredos are surmounted by two figures of angels.
In the south wall of the sanctuary is a stained glass window of St. Peter and St. John.
The carved wooden altar is set off by embroidered frontals, whilst the sanctuary floor consists of richly decorated tile flooring with marble steps.
To the left, hidden behind the organ is the choir vestry. The organ itself came from Holy Trinity Church in 1903 and was made by J.W. Walker & Sons Ltd. It was moved and refitted at a cost of £60. It was rebuilt in 1934 and completely overhauled between 2001 and 2003 (see Music).
The Bishop's throne was constructed by the same craftsman who made the font cover, Mr Rod.
Carved stone was the original choice for the chancel screen but this was later surmounted by one of wrought iron with gates. This was erected by Dr. R. Heath in memory of his young daughter in about 1930. It has long been the subject of controversy with discussions about its removal in 1959 and again during the seventies and eighties. The carpeted wooden platform at the bottom of the chancel steps is a recent addition.
The pulpit is of carved oak on a stone base. The carved figures are The Good Shepherd, St. Paul and St. Luke. Opposite the pulpit, on the right hand side of the chancel screen is a painted statue of St. Paul.
To the right of the chancel is the Lady Chapel, apsidal in shape, but simple and attractive. It is used for weekday Masses. The windows were donated during the early years of the 20th century and depict St. Margaret, Our Lady, Mary of Bethany, Martha of Bethany, St. Agnes, St. Martin and St Alban.
The Sacrament House on the right-hand wall is in memory of Hilda Dix and Alfred and Dorothy Scriven. It contains the Blessed Sacrament (the Consecrated Bread of the Eucharist) and is the focus of Christ's Real Presence in our lives.
The small hanging rood shows Christ on the Cross with Our Lady and St. John. It is in the Faithcraft style, similar to the Sacrament House and the altar candlesticks.
The altar (made of oak) incorporates the altar top given to the church years ago in memory of the Adlam family.
The statue of Our Lady is made of painted limewood and came from Italy.
In the south aisle the windows depict St Michael, St George, St Andrew, St. John and St. Paul.
Standing alone to the left of the south door is the memorial window for Canon Fisher depicting St. Aldhelm.
The final group of windows is in the north wall, close to the door showing The Venerable Bede, Jesus the Light of the World and Jesus the Good Shepherd.
On the wall just inside the north door is a holy water stoup, carved in the form of cupped hands by Paul Davies.
Against the North wall is a small altar to Our Lady of Walsingham. The statue of our Lady of Walsingham was restored in 2006.
The children's corner is a recent replacement. It first appeared in 1935, but disappeared for many years. Also in this corner is the Sunday school banner, of Christ with children. Faith material suitable for young people is available here.
Finally, around the walls are fourteen oil paintings of the Stations of the Cross, used each year in Lent to trace the saving journey of Christ to Calvary.