There is always some Scripture that concludes a matter of debate in the church:
Though he were a Son, yet learned he obedience by the things which he suffered; And being made perfect, he became the author of eternal salvation unto all them that obey him.
There is eternally secure salvation, just not unconditionally: there must be obedience to the faith. (Rom 1:5)
If we are to be raised together in the likeness of His resurrection, then we must walk together in the manner of His steps by obedience.
The forerunner of our salvation set the example of obedience, even unto the death of the cross.
Salvation begins the race of everlasting life by grace through faith, and ends in resurrection of life with obedience to the faith by grace. Without obedience, faith is dead, and grace cannot save through dead faith.
Once we cease obeying the faith, then we turn from the faith: a race half-run is as a cake half-turned.
The grace of God is given to the believer for help in time of need to overcome temptation, not to be excused in sin: no person sins under grace, with grace, nor graciously.
The grace of God is neither conditional nor unconditional, it is necessary for use in salvation. (Titus 3:14)
We either use it, or lose it. We must grow in grace by obedience, or fall from grace by rebellion.
If we reject the help of grace to overcome sin, then we despise the Spirit of grace for the sake of sin.
Those rejecting grace by willful disobedience to the Word of God are not under grace, but under condemnation:
The soul that sinneth, it shall die.
God is not a respecter of persons, excusing the sins of one while judging the same sins of another.
The LORD is slow to anger, and great in power, and will not at all acquit the wicked.
Unconditional eternal security and obedience to the faith do not mix, no more than bitter water and sweet:
Your glorying is not good. Know ye not that a little leaven leaveneth the whole lump? Purge out therefore the old leaven, that ye may be a new lump, as ye are unleavened. For even Christ our passover is sacrificed for us.
Faith is the lump, obedience is the purge.