A gift can be conditional though.
Heb 5:9 And having been perfected, He became the author of eternal salvation to all who obey Him,
Salvation is the gift. There's nothing we can do to earn that gift. But God can grant it based on the condition of obedience.
I'll give you a present if you come to the party...but I'm not going to see you out and give you the gift if you don't come to the party.
The only condition on God's gift is that we receive it by faith. Any work that must be done to either get OR keep the gift renders it no longer a gift.
Heb 5:9 And having been perfected, He became the author of eternal salvation to all who obey Him,
What does God call us to "obey"? Jesus answered this:
Salvation is the gift. There's nothing we can do to earn that gift. But God can grant it based on the condition of obedience.
The obedience God requires is FAITH. For us to believe. Our good works do not earn grace because grace would cease to be grace.
Again, God requires faith for us to receive His gift of eternal life. That's how we "come to the party".