Christianity teaches that there is one God, with three personas. We know these as the Father, the Son, and the Holy Ghost. All three of these are the same, one God. We can tell them apart because they have different roles, different work, and different ways of relating to us.
God the Father created and sustains everything. Only the Father knows when the end of creation will come. This is very heavy knowledge. Maybe the Father keeps this knowledge to Himself as a gift to the Son and to the Holy Ghost, (who are also Himself,) so that they will not be burdened with this heavy knowledge as they go about their work.
God the Son, Jesus, trusted God the Father with information He did not know. He knew God was somehow Himself, and that He is love, and that He can be trusted. The Son lived as a person, so as someone who people can relate to and love. I think Jesus mentioned that He saw the creation of everything. This is different from doing the creating, which was done by the Father.
God as the Holy Ghost can live in our hearts, and remind of things that help us live our lives. This is also very mysterious.
There are also different religions that teach there is one God, but with a different name or personality than Christianity’s God. I understand that some religions have many different names for the same God. And some religions just have many different Gods. Maybe this is all God with different personalities in different situations.
It may be that this is one of the ways in which we are created in the image of God, as we also each seem to have multiple personalities. Who has not seen a parent exhibit a completely different personality when talking with their toddler than when speaking at a meeting at work, or than when they are alone with someone they love? Or who has noticed there is some knowledge that was lost, that we remember again when something reminds us of that time we lived through, then had forgotten, a photo, or a phrase, or maybe a smell. Who hasn't lost track of what day it is? Or noticed somebody else has done this?
Sometimes we seem like different people when we are in different situations. Sometimes we feel like different people. OK, for different reasons, some of us definitely exhibit this more than others. But I think this is OK. This is how God created us, in His own image.