Eph 1:5-8, 18-19, 2:12-13 and 19, Rom 8:15-17
People use verses to justify predestination. We were all predestined to be saved. It is God's perfect will. Salvation is a gift, the ultimate expression of His love for us; and He created us specifically so that He could express His love. Free will is part of that design. Without free will, there is no such thing as unconditional love! Love risks being rejected and scorned so that it can be fully expressed. If I act motivated by fear of abandonment, rejection, or disapproval, I am not acting with love.
My response to grace is also part of God's perfect will. He created us with the capacity and purpose to love. Free will is also part of this plan. Without free will, I am not loving. I'm just going through the motions.
The work of the Holy Spirit in drawing people to Christ is also part of this plan. Without the Spirit's nudging, free will does not exist. A person cannot reject what he has not heard. And we cannot reject what our hearts are not open to consider. So our sharing the truth and the Spirit's work in people's hearts are part of God's plan.
God responds to our expression of love by enabling us to remain in Christ and keep His commandments. Living in legalism stifles love, but living in deliberate love will never conflict with the law. Christ did not come to abolish the law but to fulfill it.