MYSQL Query

<?php
session_start();
 if(!$_SESSION['email']){
    header("Location:index.php");
    exit();
 }


    $query = " INSERT INTO employees(first_name,last_name,middle_
name,gender,social_security,dob,
organization,department,iden,position,
pay_rate,health_plan,dental_plan,vision_plan,address_one,address_
two,apartment,city,_state,zipcode,primary_phone,email) VALUES
($first_name,$last_name,$middle_name,$gender,$social_security, 
$dob,$orangization,$department,
$identification,$position,$payrate,
$healthcare,$dental,$vision,
$address_one,$address_two,$apartment,
$city,$state,$zipcode,$phone_number,$email)";
    $insert_query = mysqli_query($connect,$query);

    if($query) {
       echo "Query Failed"."<br>".mysqli_error($connect);

       exit();

    } else { echo "Success";}
  }


//output
Query Failed
You have an error in your SQL syntax; 
check the manual that corresponds to your MariaDB server version for the right syntax to use near
 'Stack Developer,50.00,MetroPlus,Cigna,Guardian,400 John blv,300  Dav Blvd,' at line 1
?>