Psalm 119:68 Thou art good, and doest good; teach me thy statutes.
Psalm 119:73 Thy hands have made me and fashioned me: give me understanding, that I may learn thy commandments.
Psalm 119 – what a chapter! 176 verses (the longest in the Bible) and all but 2 directly mention the word of God (word, statutes, judgments, law, commandments, etc.). Its structure is curious. It has 22 sections, each with 8 verses. Each section corresponds to and begins with a letter of the Hebrew alphabet – in order. That is, the first section begins with "aleph," the second with "beth," and so on (see the headings in your Bible).
One of the many great things about the Bible God has given us is that it not only tells us what we ought to do, in many cases, it tells us just exactly why we ought to do it.
Now, God has every right to give us one of those parental BECAUSE I SAID SO'S – but he doesn't! The Bible is full of arguments and reasons for why we should do what's right. The individual who says that serving God doesn't really matter just as long as you're saved is obviously one who isn't carefully reading the scriptures.
For example, here in Psalm 119 the Lord very clearly lays out 2 very sound lines of reasoning as to why we should seek to learn and obey His word.
1. Because God is good (v. 68)
God is love (1 John 4:8). And somehow, someway, for some unknown reason, He has chosen to extend that love to us. His commandments, His instruction, His rebuke, His chastening, are only extensions of that love. If we could settle in our minds and hearts that God's commandments have been issued with the object of our well-being, it seems we'd do a much better job of staying in line.
See Deuteronomy 10:13; Psalm 34:10-22; Psalm 37:4, 23, 37; Jeremiah 7:6, 19, 23; Jeremiah 25:7; Micah 2:7; Acts 3:26; 1 John 5:3.
2. Because God is God (v. 73)
The fact that God made us argues very strongly for the fact that He's got things figured out a whole lot better than we do. I mean, do we really think that we know better than God? No sane person would ever admit that, but sometimes we sure act like that's what we're thinking.
Isaiah 55:8-9 For my thoughts are not your thoughts, neither are your ways my ways, saith the LORD. For as the heavens are higher than the earth, so are my ways higher than your ways, and my thoughts than your thoughts.
Romans 9:20 Nay but, O man, who art thou that repliest against God? Shall the thing formed say to him that formed it, Why hast thou made me thus?