Lord.
The Most High God has many names. Jehovah, Yeshua (Jesus), God the Father, Holy Spirit.
But since God is the Lord of my life, I opt for Lord, ABBA (for father) and Jesus and Holy Spirit. It depends on what I am speaking to Him about.
as his dad or father.
They should be submissive to God.
It should be that all Christians worship and praise same God.
Catholics do call God father. Not to do so would be heretical as Jesus, himself, said we should address him as Our Father.
So they can talk with God or Jesus
yes
To obey God.
No, Christians believe that there is only one God and that is the God of the Bible, who is the creator of all. he alone is worthy to be worshipped.
Read the Holy Bible and pray to God.
Christians relationship with god i to let him be your savior
True Christians prove their devotion to God by obeying God in the spirit.
To get closer to God...mostly...or fellowship with others christians....
Christians believe him to be God and therefore worship him as God.