***** ... they teach that our salvation depends on Gods choice rather than on our own. Such a teaching can also lead to the idea that Gods grace is only for a few and that, once saved, a person cannot choose to be lost. ********
First, Joshua 24:15 is not a text teaching we have our own choice in salvation. It is constantly misrepresented as such. Joshua gives the people a choice between serving the evil gods of the past or the evil gods of the Amorite neighbors. The point was they were hypocrites with a long history of rebellion against God.
Next, 1Tim 2:4 is no help for you either. The fact that God will have "all men to be saved" is not saying "all men will be saved" or even "God wants all men to be saved but can't make it happen because you have free-will". What does it say? Simply, that it is God's plan to save everyone that He plans to save. How do we know it isn't applied to the entirety of mankind? Because it was Christ who in the next verse (6) is stated as he "Who gave himself a ransom for all..." IF we take your position, which is, that Christ paid the complete penalty for all men then you have a big problem. The same "ransom" or substitutionary atonement that pays the entire sin debt for the forgiven also pays the SAME ransom for those who reject Christ until the day they die. See the problem? It's real and unavoidable.
But, of course, in truth Christ didn't die for all men everywhere, but He did die for all men who were given to Him by the Father, and these "all men" will be saved. They are saved because Christ gave Himself a ransom - His Righteousness for their Wickedness. It is a transaction that occurs in the court of heaven - not because people 'choose'. Understand?
Read 2Cor 5:15, where the same idea is presented: Christ "died for all" and because of this those "which live" - spiritually, are henceforth "do not live unto themselves" but rather they are "a new creature". Why does the Bible say this? Because God has reconciled "us to Himself by Jesus Christ". Why is this important? Those whom Christ died for are to be reconciled to God; they are made "alive" via regeneration by the Holy Spirit and no longer desire to live to themselves. They are made a new creature with a new living spirit. Now think about this for a moment. God gave Christ to be a "ransom for all", that is "one died for all", you see both passages are teaching that God's salvation is effectual - it was specific, it actually redeemed the men for which it was done. Not all mankind everywhere but all mankind who were loved by God from before the foundation of the world and chosen to be saved. Not the whole world, but these particular ones are those that the Holy Spirit regenerates - those whom Christ gave Himself in death, they are reconciled to God, they are redeemed, they are made righteous by Christ's substitutionary atonement.
So, it is not correct to say God simply wants all men saved. It is not correct to say that Christ died for the opportunity of all men to possibly be saved. Rather, the Bible never waivers on this: God the Father chose all He wanted saved from His judgment against mankind and gave these same people for His Son to ransom, all before the world was formed. These chosen are redeemed and reconciled to God each at their appointed time as dictated by the plan of God (apart from your personal desire in the matter too - for in truth, man's desire apart from regeneration is to be like their father the Devil - full of hatred for God and His people).
How ludicrous it would be for Christ to endure the entire penalty of hell until the very last drop of punishment has been finished - and then throw His ransomed work into hell to pay the same penalty on judgment day. It would be like a man who generously pays a poor man's million dollar debt so he is legally freed - and later charges the poor man's debt back upon him again and throws him into debtor
