Answer:
Iconography represents presentation of Jesus Christ, Virgin Mary, apostles and other motifs from the Bible. Church used it to strengthen its authority among the believers and to spread Christianity among believers.
Step-by-step explanation:
Question of usage of iconography in Churches was a question that was risen in the Middle Ages. In the Renaissance many artists were included in this process. Just take for the example the Sistine Chapel and works that Michelangelo managed to finish there. Church influenced many people with this and tried to strengthen its role.