Ping!
Not sure if Luther continued in the Reformed tradition, but certainly the understanding of the “gift” of salvation by grace through faith was clarified later by TULIP. And, this is often neglected nowadays, even by some who claim the “reformed tradition”. The Scriptures teach:
Total depravity (inability to come to Christ)
Unconditional election (chosen before the foundation of the world)
Limited Atonement (Christ died for the elect)
Irresistible Grace (If a person is among the elect, they will be “drawn” without fail)
Perseverance of the Saints (All the elect will be kept by Jesus and raised up on that day)