The Holy Ghost - the Spirit of Jesus in us - is not just a good thing to have - the Holy Ghost is necessary to be saved!

"Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God." - John 3:5 KJV

If we are not filled with the Spirit of Jesus, the Bible says we are none of His!

"There is therefore now no condemnation to them which are in Christ Jesus, who walk not after the flesh, but after the Spirit. ... But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwell in you. Now if any man have not the Spirit of Christ, he is none of his." - Romans 8:1, 9 KJV

How are we born of the Spirit? And how are we filled with the Holy Ghost?

We are born of the Spirit and filled with the Holy Ghost just like they were on the day of Pentecost. Jesus commanded His disciples to wait for the promise of His Spirit which He would soon pour out.

"And said unto them, Thus it is written, and thus it behoved Christ to suffer, and to rise from the dead the third day: and that repentance and remission of sins should be preached in his name among all nations, beginning at Jerusalem. And ye are witnesses of these things. And, behold, I send the promise of my Father upon you: but tarry ye in the city of Jerusalem, until ye be endued with power from on high." - Luke 24:46-49 KJV

"And when the day of Pentecost was fully come, they were all with one accord in one place. And suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting. And there appeared unto them cloven tongues like as of fire, and it sat upon each of them. And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance." - Acts 2:1-4 KJV

Peter preached the gospel to all those that saw and heard the disciples as they received the promised Holy Ghost.

"Now when they heard this, they were pricked in their heart, and said unto Peter and to the rest of the apostles, Men and brethren, what shall we do?

“Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost.

“For the promise is unto you, and to your children, and to all that are afar off, even as many as the Lord our God shall call.

“And with many other words did he testify and exhort, saying, Save yourselves from this untoward generation.

“Then they that gladly received his word were baptized: and the same day there were added unto them about three thousand souls." - Acts 2:37-41 KJV

They repented of their sins, they were baptized in Jesus name, they received the gift of God’s Spirit - the Holy Ghost.

"And they continued stedfastly in the apostles' doctrine and fellowship, and in breaking of bread, and in prayers.

“... And the Lord added to the church daily such as should be saved." - Acts 2:42, 47 KJV