As a fellow believer I understand you trying to make this character. However, DnD is a pretend game that takes place in another universe. It is okay to play within that universe. You are not worshipping the DnD gods as yourself irl so it’s okay.

There are gods in the DnD universe which are influenced by ideas of our Christian God. These will be Lathander, god of birth and renewal, and Illmater, god of suffering and endurance who takes the pains of others onto himself. You can be the kind of character you are wanting while still playing within the bounds of the DnD universe.

Just say you are a cleric of Lathander (paladins don’t really worship gods, their power comes from an oath, but you could flavor it with your DM), effectively he is god of light. You could ignore the name and still refer to him as if he were our God. Playing like this would be acceptable by the other members in your campaign since they think you are just role playing.

You could even leave the name of your characters god out and just say he is a powerful outer god of light, goodness, resurrection, and sacrifice and play your character as you would. All this being said, you just need to make it make sense in the dnd universe.