SQL & PL/SQL :: Select Data From Test-1 Table Where ID Values In Table Exists In 2?

I have the below data in table test_1.

select * from test_1
IDNameTotal
-----------
1A100
2B100
3C100
4D100

test_2 table contains the concatination of ID's with comma seperated. Actually in this table ID column is of datatype varchar2.
select * from test_2
ID
----
1,2,3

My requirement is to select the data from test_1 table where the id values in this table exists in test_2 table. I tried with the belowselect statement, but could not get any data.

SELECT * FROM test_1 WHERE to_char(id) IN (SELECT id FROM test_2)

create table test_1 (id number, name varchar2(100), total number)
create table test_2(id varchar2(100))
insert into test_1 values (1,'A',100)
insert into test_1 values (2,'B',100)
insert into test_1 values (3,'C',100)
insert into test_1 values (4,'D',100)