Why the current is equal in each resistor of a series circuit?

where else it would go through.....

the current entering the first resistor must pass through the next preceding resistors in order to reach the positive/+ve potential so as to complete the circuit.

Current flow is the actual flow of electrons so it goes from the ground (negative most point) to th emost positive point. lectrons are a negatve charged unit so they travel towards the positive point.