What you said is quite true - but only partly true.  Scripture also teaches us that salvation comes to us at a great cost.  Taking up our cross to follow Him shows us there is great responsibility in being faithful stewards of this great gift.  We can't do anything ourselves to attain the gift of salvation, but we have the choice to yield to or resist the perfecting work of salvation in our lives by His Spirit.  After all, salvation is only the beginning - becoming Christ-like is our ultimate goal.