Tit 2:11-13 For the grace of God that brings salvation has appeared to all men, teaching us that, denying ungodliness and worldly lusts, we should live soberly, righteously, and godly in the present age, looking for the blessed hope and glorious appearing of our great God and Savior Jesus Christ,
The grace of God is given freely to all men so that whosoever responses to His grace will be saved. Whoever believes the everlasting gospel will be saved for God is faithful in keeping His part of the covenant. If anyone claims that he is a born again Christian but still is unable to deny ungodliness, worldly lust, etc. nor to live soberly nor righteously, then he may be unsaved in the first place.
John 3:16 "For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life."
Eph 2:8 For by grace you have been saved through faith, and that not of yourselves; it is the gift of God,
The Saving Grace of God is our faith (believing, accepting and confessing) in Christ Jesus as the Lamb of God, who died as the propitiation for our sins, etc. and His resurrection (found also in the Apostle Creed)
Eph 1:7 In Him we have redemption through His blood, the forgiveness of sins, according to the riches of His grace.
Eph 1:12-13 that we who first trusted in Christ should be to the praise of His glory. In Him you also trusted, after you heard the word of truth, the gospel of your salvation; in whom also, having believed, you were sealed with the Holy Spirit of promise,
This saving Grace does not only redeem us by forgiving our sins but also gives us the Holy Spirit as a seal of redemption.
Saving Grace = Salvation
+ Holy Spirit as the Seal
The Holy Spirit (by the Grace of God) will help us to understand His attributes, will, words, truth, etc. and also to know sins, righteousness, judgment, etc. The gifts of the Holy Spirit will empower us in our works and ministries. However, the unsaved, without the Holy Spirit, cannot understand scriptures thus resulting to them teaching wrong doctrines and distorted truth.
1Cor 6:19-20 Or do you not know that your body is the temple of the Holy Spirit who is in you, whom you have from God, and you are not your own? For you were bought at a price; therefore glorify God in your body and in your spirit, which are God's.
Whenever we sin, our body is filled with our sins. The Holy Spirit dwelling inside our body will be completely immersed in our foul and nauseating sins (Imagine yourself thrown into the foul, revolting and nauseating pond filled with excreta with worms getting into your nose, eyes and ears). Even under such great sufferings and grief, the Holy Spirit will not leave us otherwise we will lose our salvation.
Eph 4:30 And do not grieve the Holy Spirit of God, by whom you were sealed for the day of redemption.
1John 1:9 If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.
We thank God for the conviction of our sins by the Holy Spirit so that immediately after our repentance, all our sins will be cleansed and the Holy Spirit dwelling in us will not have to suffer the horrific and revolting sins nor be grieved any further.
Brethren, it is easy to recognize wrong doctrines and heresies for they will always contradict God's attributes, and Jesus' promises, words, teachings, etc. (at times these heresies reduce our Lord Jesus to be a deceiver or liar).