Can a Believer in the Trinity Have a Relationship with God?

The vast majority of Christian churches and preachers teach that the Trinity doctrine is true, and is a vitally important Biblical message. On this basis, therefore many sincere Christians believe in the Trinity doctrine. Can a believer in the Trinity have a relationship with God?
“It is God who judges”—Psalm 75:7 NIV;
“God is a righteous judge”—Psalm 7:11 NIV
“He is a God of justice”—Psalm 50:6 NIV
“Why do you judge your brother or sister?”—Romans 14:10 NIV