Tribulation Salvation by Blood

The controversy surrounding how a person is saved in the Tribulation: I was taught that their salvation involved faith PLUS works, but now believe that they too will be saved by trusting in Christ. The outline:

Point #1: Those who take the Mark are deceived
Point #2: Salvation is by the blood
Point #3: Believers are called fellowservants; brethren & saints. Matthew refers to the believers as the "elect."
Point #4(S): Self defense is forbidden
Point #5(S): Keep the commandments for testimony
Point #6: Those with the Mark are deceived and it is impossible for the saved to be deceived.
Point #7: The saved accept the truth for salvation.
Point #8: Whosoever calls upon the name of the Lord shall be saved (delivered in Joel 2).