They may agree with the phrase ''once saved, always saved'' but the problem with that term is the what they mean by it,.. I don't see the relation when ask for a more clearer definition .. I have heard that it means that despite what you may do, and that relates to falling back towards our sin nature and to practice as such, you still are not liable to lose your salvation, which excuses the sin that they maybe committing at the time, with the excuse that ''once saved, always saved'',.. so I do not like using it, and feel the more prone to the accept the above explanation as it put God as the author and finisher of the faith given as a gift.... They no longer have a struggle with sin, they give in and hold to the OSAS mantra,.. here's a quote from Michael Horton, briefly on the term,.. not fully agreed to the degree, it could have been fleshed out more, but here it goes.. ''When we speak of “once saved, always saved,” we are not taking into account the full scope of salvation. We have been saved (justification), was are being saved (sanctified), and we will one day be saved (glorified). You cannot claim to have been “saved” (justified) unless you are being sanctified. Jesus Christ is Savior and Lord.
Michael Horton from Putting the Amazing Back into Grace (pg. 171)

"A man may be theologically knowing and spiritually ignorant." STEPHEN CHARNOCK