1. Those who believe in Jesus as Lord and Christ will be saved. (Joel 2:32)
    Acts 2:21-22,36, Rom 10:9-13, 1 Cor 1:2

In the Old Testament, God said that those who call on His name will be saved. (Joel 2:32)

Joel 2:32 And it shall come to pass, that whosoever shall call on the name of the Lord shall be delivered: for in mount Zion and in Jerusalem shall be deliverance, as the Lord hath said, and in the remnant whom the Lord shall call.

Calling on the name of the Lord as spoken of in the Old Testament is believing in Jesus as Lord and Christ. Anyone who believes in Jesus as Lord and Christ will be saved. (Acts 2:21-22, Romans 10:9-13, 1 Corinthians 1:2)

Acts 2:21 And it shall come to pass, that whosoever shall call on the name of the Lord shall be saved.
22 Ye men of Israel, hear these words; Jesus of Nazareth, a man approved of God among you by miracles and wonders and signs, which God did by him in the midst of you, as ye yourselves also know:

Romans 10:9 That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved.
10 For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation.
11 For the scripture saith, Whosoever believeth on him shall not be ashamed.
12 For there is no difference between the Jew and the Greek: for the same Lord over all is rich unto all that call upon him.
13 For whosoever shall call upon the name of the Lord shall be saved.

1 Corinthians 1:2 Unto the church of God which is at Corinth, to them that are sanctified in Christ Jesus, called to be saints, with all that in every place call upon the name of Jesus Christ our Lord, both their’s and our’s: