All we need to prove that obedience is one of the conditions for salvation is the written word of God.
“He who believes in the Son has eternal life; but he who does not obey the Son will not see life, but the wrath of God abides on him.” (John 3:36). This passage tells us those who do not obey will not see eternal life but will face the wrath of God.
By this we know that we have come to know Him, if we keep His commandments. The one who says, “I have come to know Him,” and does not keep His commandments, is a liar, and the truth is not in him; but whoever keeps His word, in him the love of God has truly been perfected. By this we know that we are in Him: the one who says he abides in Him ought himself to walk in the same manner as He walked. (1 John 2:3-6). This passage tells us those who profess to know him but do not obey him are liars.
Who should we trust here? Those who say we obey because we love but if we do not obey we are still saved? Or should we obey Jesus who said “If you love me you will obey me” and “Why do you call me Lord Lord and not do what I say”. Clearly from Jesus`words obedience is a condition for salvation.