Can someone please point me in the right direction?hanks.

Error Message: Non-selective query against large object type (more than 100000 rows). Consider an indexed filter or contact salesforce.com about custom indexing. Even if a field is indexed a filter might still not be selective when: 1. The filter value includes null (for instance binding with a list that contains null) 2. Data skew exists whereby the number of matching rows is very large (for instance, filtering for a particular foreign key value that occurs many times)
Error System Trace: Class.HelperClass.newEval: line 982, column 1 Trigger.triggername: line 36, column 1

trigger triggername on Object__c (after insert, after update) {

 if(trigger.isInsert){
        List<Object__c> evaluations = [Select Id From Object__c];
    
        Map<Id, List<Id>> junk = new Map<Id, List<Id>>();
        for (Object__c obj : evaluations) {
        
            junk.put(obj.Id, new List<Id>());   
        }

        for (Employee_Object__c empobs : Trigger.new) {
            if (junk.containsKey(empobs.Object__c)) {
                junk.get(empobs.Object__c).add(empobs.Id);            
            }       
        }
    
    
        
        HelperClass.newEval(trigger.new); // line36        
    }
 ......
 
}

public without sharing class HelperClass {
  public static void newEval(list<Object__c> newEV){
        try {
            //Get List of Employee IDs, OS
            set<id> empIDs = new set<id>();
            set<id> cnIds = new set<id>();
            for(Object__c ev: newEV){
                empIDs.add(ev.Employee__c);
                cnIDs.add(ev.Group_Leader_Id__c);
            }
            list<Employee__c> emps = [select id,Manager_Id__c,Group_Leader_Id__c,SC_ID__c from Employee__c where id in:empIDs];
            map<id,Employee__c> mp_emps = new map<id,Employee__c>(emps);
            
            //Get User IDs from Contact         
            for(Employee__c e: emps){
                cnIds.add(e.Group_Leader_Id__c);
                cnIds.add(e.SC_ID__c);
            }
            
            list<user> usr = [select id, contactID from user where contactID in: cnIDs]; // line982            map<id,id> usrIDs = new map<id,id>(); //first ID is the Contact
            for(user u:usr){
                usrIDs.put(u.contactID,u.id);
            }
   
   
   .......

}