All Christians are mandated for service and ministry, per the Great Commission. In fact we are the one and only true preachers of this present age. So by your standard of measure we also elect to service, foreordained before we were ever born. Which by the way I agree to.
The context of the elect is the nation of Israel. They were elected by God to bring forth the seed line of Christ. Paul suffered trouble through them.
8 Remember that Jesus Christ of the seed of David was raised from the dead according to my gospel:
9 Wherein I suffer trouble, as an evil doer, even unto bonds; but the word of God is not bound.
10 Therefore I endure all things for the elect's sakes, that they may also obtain the salvation which is in Christ Jesus with eternal glory.
True,,, there was an elect remnant among Israel ,
isa1:9 Except the Lord of hosts had left unto us a very small remnant, we should have been as Sodom, and we should have been like unto Gomorrah.
however the elect gentiles were grafted in Romans 11.
13 For I speak to you Gentiles, inasmuch as I am the apostle of the Gentiles, I magnify mine office:
14 If by any means I may provoke to emulation them which are my flesh, and might save some of them.
15 For if the casting away of them be the reconciling of the world, what shall the receiving of them be, but life from the dead?
16 For if the firstfruit be holy, the lump is also holy: and if the root be holy, so are the branches.
17 And if some of the branches be broken off, and thou, being a wild olive tree, wert grafted in among them, and with them partakest of the root and fatness of the olive tree;
18 Boast not against the branches. But if thou boast, thou bearest not the root, but the root thee.
19 Thou wilt say then, The branches were broken off, that I might be grafted in.
20 Well; because of unbelief they were broken off, and thou standest by faith. Be not highminded, but fear:
21 For if God spared not the natural branches, take heed lest he also spare not thee.
22 Behold therefore the goodness and severity of God: on them which fell, severity; but toward thee, goodness, if thou continue in his goodness: otherwise thou also shalt be cut off.
23 And they also, if they abide not still in unbelief, shall be grafted in: for God is able to graft them in again.
24 For if thou wert cut out of the olive tree which is wild by nature, and wert grafted contrary to nature into a good olive tree: how much more shall these, which be the natural branches, be grafted into their own olive tree?
25 For I would not, brethren, that ye should be ignorant of this mystery, lest ye should be wise in your own conceits; that blindness in part is happened to Israel, until the fulness of the Gentiles be come in.
26 And so all Israel shall be saved: as it is written, There shall come out of Sion the Deliverer, and shall turn away ungodliness from Jacob:
27 For this is my covenant unto them, when I shall take away their sins.
28 As concerning the gospel, they are enemies for your sakes: but as touching the election, they are beloved for the father's sakes.
29 For the gifts and calling of God are without repentance.
30 For as ye in times past have not believed God, yet have now obtained mercy through their unbelief:
31 Even so have these also now not believed, that through your mercy they also may obtain mercy.
32 For God hath concluded them all in unbelief, that he might have mercy upon all.
33 O the depth of the riches both of the wisdom and knowledge of God! how unsearchable are his judgments, and his ways past finding out!
34 For who hath known the mind of the Lord? or who hath been his counsellor?
35 Or who hath first given to him, and it shall be recompensed unto him again?
36 For of him, and through him, and to him, are all things: to whom be glory for ever. Amen.