[cheekopekman]

He wanted u to agree that salvation needs work not by grace lah
If u agree he wins

You put that very succinctly, bro. Whatever we say, he's sure to disagree with us. He has to, no matter how persuasive the arguments or evidences we put up. Because if he concurs, it means his beliefs, which are diametrically opposed to ours, are false and our beliefs are true.

He holds an unBiblical belief of "works-based salvation," which is opposed to our "faith-based salvation, and has been rejecting the imputation of Christ's righteousness to the believer. Paul called it "a different gospel" (Gal 1:6,9). The same error is found in virtually every false cult. Every "different gospel" is under the eternal curse of God.

If to agree with him we will fall away from faith 
Should not doubt the Bible  our daily bread to strengthen our faith in God

We must be careful how we answer questions from non-Christians, especially with regards to the Bible lah!  We must give an account of every careless word spoken 1 day lah!