One of the reasons I started to look into Calvernism properly ( as I started to lean in the direction ) Was the P in T.U.L.I.P.
Perseverance of the Saints. I do believe in Eternal security but the Calvernist version of OSAS I do not believe. My question is : Isnt the P in T.U.L.I.P essentially of Lorship / subtle works salvation?
There are different doctrines that are called "Lordship Salvation." In order to answer the question whether or not the Perseverance of the Saints teaches a form of Lordship Salvation I need to know what you mean by Lordship Salvation. The Perseverance of the Saints certainly does not teach any certain of justification by works or man's own duties. We understand that we are not our own saviors, and do not save ourselves by our own works or efforts.
But in order to understand the doctrine of the Perseverance of the Saints consider the explanation of it given in the Westminster Confession of Faith:
Chapter XVII
Of Perseverance of the Saints
I. They, whom God has accepted in His Beloved, effectually called, and sanctified by His Spirit, can neither totally nor finally fall away from the state of grace, but shall certainly persevere therein to the end, and be eternally saved.
II. This perseverance of the saints depends not upon their own free will, but upon the immutability of the degree of election, flowing from the free and unchangeable love of God the Father; upon the efficacy of the merit and intercession of Jesus Christ, the abiding of the Spirit, and of the seed of God within them, and the nature of the covenant of grace: from all which arises also the certainty and infallibility thereof.
III. Nevertheless, they may, through the temptations of Satan and of the world, the prevalency of corruption remaining in them, and the neglect of the means of their preservation, fall into grievous sins; and, for a time, continue therein: whereby they incur God's displeasure, and grieve His Holy Spirit, come to be deprived of some measure of their graces and comforts, have their hearts hardened, and their consciences wounded; hurt and scandalize others, and bring temporal judgments upon themselves.
Consider also what it says on the doctrine of the Assurance of Salvation:
Chapter XVIII
Of Assurance of Grace and Salvation
I. Although hypocrites and other unregenerate men may vainly deceive themselves with false hopes and carnal presumptions of being in the favor of God, and estate of salvation (which hope of theirs shall perish): yet such as truly believe in the Lord Jesus, and love Him in sincerity, endeavouring to walk in all good conscience before Him, may, in this life, be certainly assured that they are in the state of grace, and may rejoice in the hope of the glory of god, which hope shall never make them ashamed.
But I will need to know what doctrine it is you oppose under the name "Lordship Salvation" in order to say whether or not the Perseverance of the Saints teaches a form of Lordship Salvation.