As far as the dinosaurs go and the millions of years read 2 peter below. As far as not doing what you should to be saved fear not for you already have been saved but in our bodys the law of sin is still at work. Read romans 7, below 2 peter.
2 Peter 3:4-6 (NIV)
4They will say, "Where is this 'coming' he promised? Ever since our fathers died, everything goes on as it has since the beginning of creation." 5But they deliberately forget that long ago by God's word the heavens existed and the earth was formed out of water and by water. 6By these waters also the world of that time was deluged and destroyed.
Romans 7
7What shall we say, then? Is the law sin? Certainly not! Indeed I would not have known what sin was except through the law. For I would not have known what coveting really was if the law had not said, "Do not covet."[
b] 8But sin, seizing the opportunity afforded by the commandment, produced in me every kind of covetous desire. For apart from law, sin is dead. 9Once I was alive apart from law; but when the commandment came, sin sprang to life and I died. 10I found that the very commandment that was intended to bring life actually brought death. 11For sin, seizing the opportunity afforded by the commandment, deceived me, and through the commandment put me to death. 12So then, the law is holy, and the commandment is holy, righteous and good. 13Did that which is good, then, become death to me? By no means! But in order that sin might be recognized as sin, it produced death in me through what was good, so that through the commandment sin might become utterly sinful.
14We know that the law is spiritual; but I am unspiritual, sold as a slave to sin. 15I do not understand what I do. For what I want to do I do not do, but what I hate I do. 16And if I do what I do not want to do, I agree that the law is good. 17As it is, it is no longer I myself who do it, but it is sin living in me. 18I know that nothing good lives in me, that is, in my sinful nature.[
c] For I have the desire to do what is good, but I cannot carry it out. 19For what I do is not the good I want to do; no, the evil I do not want to dothis I keep on doing. 20Now if I do what I do not want to do, it is no longer I who do it, but it is sin living in me that does it.
21So I find this law at work: When I want to do good, evil is right there with me. 22For in my inner being I delight in God's law; 23but I see another law at work in the members of my body, waging war against the law of my mind and making me a prisoner of the law of sin at work within my members. 24What a wretched man I am! Who will rescue me from this body of death? 25Thanks be to Godthrough Jesus Christ our Lord!
So then, I myself in my mind am a slave to God's law, but in the sinful nature a slave to the law of sin.