It's not built in...the knowledge of good and evil.

Genesis 2:9 and 17, 3:1-7

Any idea of “total depravity” is destroyed by the very first moment of sin in human life.  God made a tree that had a fruit that, when eaten, gave two (yes, count ‘em, 2) painful gifts.  First, death entered into human experience as promised.  Second, the fruit juice entered human tissues and its effective capacity – that for which it was named – became a permanent part of humanity:  the knowledge of good and evil.

Salvation is the gift.

Ephesians 2:8 cannot be interpreted as though God gives the gift of faith to man in a special way.  Man exercises faith at all times whether for good or ill.  The gift mentioned in this verse is the same as the gift we find in John 3:16.  Because of His love for the world, God gave His only begotten son, Jesus.  Jesus is salvation. Jesus is eternal life.  Believe it and live it.  If you don’t know Jesus, try Him.