Like the Chi Rho, the Alpha and Omega symbol is a very ancient monogram of our Lord Jesus Christ. Based on several scripture passages in Revelation, it means that Jesus is the beginning and end of all things—the one who is, and who is to come. Alpha (Α) and Omega (Ω) are the first and last letters of the Greek alphabet. It is often used in connection with other symbols to give adding meaning, as is the case with many other sacred monograms.
While a white dove by itself is a symbol of the Holy Spirit, the addition of a flame represents the Day of Pentecost—and by extension, the Christian Church. Sometimes the dove is pictured with wings and tail aflame. In other instances, merely a flame is used to symbolize the tongues of fire, which appeared above the heads of those present on Pentecost.
The lily is one of the most commonly used symbolic flowers in Christianity. The Easter lily (lilium longiflorum) proclaims the spring's season of rebirth, and therefore is a symbol of the Resurrection. Easter lilies often adorn the sanctuary of churches on Easter morning and throughout the season. Artists of the Reformation have also used the lily in conjunction with the sword to symbolize Christ's mercy and judgment on the innocent and guilty on the Last Day.
The lily (lilium candidum) is also a symbol of virginity and purity. Many churches, including both Catholic and Protestant, have used the lily as a symbol of the Virgin Mary. This symbol reminds us that our Lord was conceived sinless of an undefiled virgin. In Christian art, Mary is often depicted holding lilies at the Annunciation, Visitation, Nativity, Presentation, and even at the Crucifixion in order to distinguish her from other figures. Often, this symbol is to remind us of Christ's human nature.
The cross is undoubtably the most popular of Christian symbols. Over the centuries, hundreds of variations have been used in heraldry, architecture, embroidery, jewelry, and stained glass windows. The cross featured above is a slender variation of the Cross Pattée (from the French for "footed cross") with piercings protruding inward (sarcelled). It is also called the Cross Formée, whose edges do not reach to the edge of a banner or shield. The Cross Pattée is one of the oldest and most popular crosses which has been used during the Crusades, by the Knights Templar, and royalty. Many variations of this cross exist no doubt due to its age, popularity, and beauty. The feet of the cross are said to mimic a chalice, or in a few instances, candelabra.
So they took Jesus, and he went out, bearing his own cross, to the place called The Place of a Skull, which in Aramaic is called Golgotha. There they crucified him, and with him two others, one on either side, and Jesus between them. — John 19:17, 18