It is a gift because what Jesus did for you, you cannot do for yourself! He paid the price! The wages of sin is death. (Romans 6:23) If you do not believe and accept that Jesus paid that price for you, then you must pay the price yourself.

Salvation is a gift, but if you think you can save yourself or that you are good enough, then go and try it. You cannot save yourself, nor are you righteous; but if you think so, go your way and try it, vainly try it, for surely when you have fanned your best works into a flame and walked by the light of the fire which you have kindled, you will lie down in sorrow and be sorely astonished that you were ever so mad as to dream of self-salvation or Justification by your own works!

You cannot save yourself! Salvation is a gracious gift, from a God who loves you. How can you acquire it? The moment you come to Christ and reach forth your hand of faith, the Gift is yours.