The word “theology” itself came from Greek θεός (theos - God) and λόγος (logos - word, reasoning). But in the modern sense, it means the study of God, rather than word “out of (ἐκ)” God. As such, we need to be aware that theology is a human construct trying to understand God from the human’s perspective, rather than the divine revelation from God.
To an extreme, bad theology is completely manmade and fabricated out of human greed in persuit of influence and power. Good theology should be based on a justifiable understanding of the Bible, but keep in mind that manmade theories are incomplete samplings that only give you an approximation of the complete picture.
You can picture theology like a Pointillism painting.

Image credit: Georges
Seurat: A Sunday Afternoon on the Island of La Grande Jatte
Or perhaps recreating a painting of Mona Lisa using paintballs.
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Or perhaps, more seriously, trying to picture the Father, the Son, and the Holy Spirit in Trinity.

Image credit: H
Agia Triada Moni Vatopediou Agion Oros
Although the concept of Trinity is biblically justifiable (even mathematically justifiable, see Trinitarian Arithmetics), we understand that this is not exactly what the Father looks like, nor the Son, nor the Holy Spirit here depicted as a dove (John 1:32). The Holy Spirit, or πνεῦμα (penuma - breadth or wind) ἅγιος (hagios - holy), also appeared as tongues of fire (Acts 2:3).
However, the greatest danger of indulging in theological studies is forgetting how you and I fit into this picture. We are not just trying to understand God as a specimen. The ultimate purpose should be to understand how we relate to God, to “love the Lord your God with all your heart and with all your soul and with all your mind” and “Love your neighbor as yourself” (Matthew 22:37-40). Also to “encourage one another and build one another up” (1 Thessalonians 5:11).