For there is one God, and one mediator also between God and men, the man Christ Jesus
1 Timothy 2:5
We only serve and believe in one God, who was manifested in the person of Jesus Christ. To pray to anyone else besides the Lord is a sin, making Jesus one of many that can help you in sanctification, for only Jesus was the One who died for your sins. No one else can take the place of mediator but Jesus alone.