What was this thing, the »Trinity?« Does this mean you believe in three Gods?
No. The Bible tells us in many places that there is only one God (Deuteronomy 6:4; Isaiah 43:10; 1 Timothy 2:5; 1 Corinthians 8:6). But it also tells us that three Persons are this same God‑the Father (John 17:3, 1 Corinthians 8:6; 1 Peter 1:2), the Son Jesus Christ ( John 1:20:28; Philippians 2:6,7, compared with John 5:18, Titus 2: 13; 2 Peter 1:1), and the Holy Spirit (Acts 5:3,4, Hebrews 9:14).
But that sounds crazy! How can three Persons be one God?
I'll admit it sounds unusual. We aren't used to seeing any humans who are more than one person, but that doesn't make it impossible. The key is for us to remember that being and personhood are different kinds of things.
What do you mean?
Look around you. You see lots of different beings‑a rock here, a tree there, a building over there, a cow out in the field. All of these are beings, but they aren't persons at all‑they don't have the three attributes of personhood, intellect, emotions, and moral free will. On the other hand, you see some beings that are persons‑every man, woman, and child you see is both a being and a person.
So we know that some beings are not persons at all. and some are one person. But there's nothing that tells us no being could be more than one person.
So long as you remember the difference between being and person, while it may be strange to think of a single being being three persons, it isn't illogical and should not be impossible to believe.
This is why Jesus instructed His followers about initiating people into Christianity and told them to baptize »in the name of the Father and the Son and the Holy Spirit« (Matthew 28:19).
Maybe it's not illogical, but it's pretty hard to understand.
Shouldn't we expect many things about God to be hard to understand? After all, God has more power and more intelligence than all the universe, and we are only beginning to understand our tiny corner of the universe.