Because God has directed us to be ready to explain, when we are asked...and you asked. Acts 13:48, those appointed to eternal life believed. QED: If you believe, then you were appointed to believe. Is it troubling that the God of the universe, transcendent and sovereign, high and lifted up, Holy, Holy, Holy can manage your mind as well as the 10 to the 67987789666 molecules in our bodies? Perhaps your God is as tiny as the icons on your mantle.
Of course you have no free will, if by that you mean you function independent of God. If you mean that you must be able to "feel" His control of your mind and your behavior or it does not exist, then you are simply mistaken. Proverbs 21:1, "The king's heart is like a channel of water in the hand of the Lord. He turns it wherever He wishes." What kind of believers are we? This kind of persuasive description of God is throughout the Scriptures.
Romans 9:19. Paul clearly recognized that it would be troubling to hear that you are held guilty when you are held captive by His will. His answer? Too bad that this bothers you, but God is able to do whatever He wishes and He is not unjust in doing so. This is precisely why the man-made religion of Rome is not biblical. Notice the semi-pelagian argument coming out of the woodwork, now.
As to the existence of free will:
Behold I set forth in your sight this day a blessing and a curse: A blessing, if you obey the commandments of the Lord your God, which I command you this day: A curse, if you obey not the commandments of the Lord your. God, but revolt from the way which now I shew you, and walk after strange gods which you know not.The Scriptures also declare that we can resist God's will:
Deut. 11:26-28If there is no free will then there can be no obeying nor revolt since all our actions are by the will of God.
Consider that I have set before thee this day life and good, and on the other hand death and evil: That thou mayst love the Lord thy God, and walk in his ways, and keep his commandments and ceremonies and judgments, and thou mayst live, and he may multiply thee, and bless thee in the land, which thou shalt go in to possess. But if thy heart be turned away, so that thou wilt not hear, and being deceived with error thou adore strange gods, and serve them: I foretell thee this day that thou shalt perish, and shalt remain but a short time in the land, to which thou shalt pass over the Jordan, and shalt go in to possess it. I call heaven and earth to witness this day, that I have set before you life and death, blessing and cursing. CHOOSE therefore life, that both thou and thy seed may live: And that thou mayst love the Lord thy God, and obey his voice, and adhere to him (for he is thy life, and the length of thy days,) that thou mayst dwell in the land, for which the Lord swore to thy fathers Abraham, Isaac, and Jacob that he would give it them.
Deut. 30:15-19God has left the choice to us and His blessings, by His decree, are dependent of the choice we make.
But if it seem evil to you to serve the Lord,YOU HAVE YOUR CHOICE: CHOOSE this day that which pleaseth you, whom you would rather serve, whether the gods which your fathers served in Mesopotamia, or the gods of the Amorrhites, in whose land you dwell: but as for me and my house we will serve the Lord.
Jos. 24:15God made man from the beginning, and left him in the hand of his own counsel. He added his commandments and precepts. If thou wilt keep the commandments and perform acceptable fidelity for ever, they shall preserve thee. He hath set water and fire before thee: stretch forth thy hand to which thou wilt. Before man is life and death, good and evil, that which he shall choose shall be given him.
Ecclus. 15:14-18Blessed is the rich man that is found without blemish: and that hath not gone after gold, nor put his trust in money nor in treasures. Who is he, and we will praise him? for he hath done wonderful things in his life. Who hath been tried thereby, and made perfect, he shall have glory everlasting. He that could have transgressed, and hath not transgressed: and could do evil things, and hath not done them.
Ecclus. 31:8-10As I live, saith the Lord God, I desire not the death of the wicked, but that the wicked turn from his way, and live. Turn ye, turn ye from your evil ways: and why will you die, O house of Israel?
Ezech. 33:11God does not declare that He desires only some of the wicked to turn away from their sins but all. God is pleading that the wicked change but the choice remains theirs.
Because I called, and you refused: I stretched out my hand, and there was none that regarded. You have despised all my counsel, and have neglected my reprehensions.By his sovereign command, God has given us the gift of free will so that we can freely choose to respond to his grace and love him as an act of our will.
Prov. 1:24-25I will number you in the sword, and you shall all fall by slaughter: because I called and you did not answer: I spoke, and you did not hear: and you did evil in my eyes, and YOU HAVE CHOSEN THE THINGS THAT DISPLEASE ME.
Is. 65:12Wherefore I also will choose their mockeries, and will bring upon them the things they feared: because I called, and there was none that would answer; I have spoken, and they heard not; and they have done evil in my eyes, and have chosen the things that displease me.
Is. 66:4And now, because you have done all these works, saith the Lord: and I have spoken to you rising up early, and speaking, and you have not heard: and I have called you, and you have not answered: I will do to this house, in which my name is called upon, and in which you trust, and to the places which I have given you and your fathers, as I did to Silo. And I will cast you away from before my face, as I have cast away all your brethren, the whole seed of Ephraim.
Jer. 7:14-15Jerusalem, Jerusalem, thou that killest the prophets, and stonest them that are sent unto thee, how often would I have gathered together thy children, as the hen doth gather her chickens under her wings, and THOU WOULDEST NOT?
Matt. 23:37You stiffnecked and uncircumcised in heart and ears, you always RESIST the Holy Ghost: as your fathers did, so do you also.
Acts 7:51