"The Son radiates God’s own glory and expresses the very character of God, and he sustains everything by the mighty power of his command. When he had cleansed us from our sins, he sat down in the place of honor at the right hand of the majestic God in heaven."
If you want to know who God is, look to Jesus Christ. Hebrews chapter one tells us that the Son of God is not an angel. He is the creator of this world. He is divine.
How God is both three persons and yet also one is not fully comprehensible. There are not three gods. The Bible teaches there is only one God (Isaiah 44:6; James 2:19). And yet the Bible also teaches that God is three persons: Jesus, the Father, and the Holy Spirit (Matthew 28:19; John 14:26; 2 Corinthians 13:14). So God is triune-three eternal beings of the same essence who are one.
To know God and to have a relationship with him requires us to submit to Jesus Christ. Jesus says in John 14:6 that no one can come to the Father except through Jesus. This makes sense given that Jesus Christ is both divine and mortal. He is the bridge, or as 1 Timothy 2:5 describes him, the mediator between God and humanity.
The next time you cross a bridge, offer a thanks to Christ Jesus. God came from heaven to earth in order to save humanity. He became human, to die, in order that we might live. He cleansed us from our sins. And if you are one of his followers, you should strive to live in a way that pleases him.