Worship your way to Joy!
There is a Puritan prayer that says: "Teach me that if I do not live a life that satisfies Thee, I shall not have a life that satisfies myself." That means that our joy, pleasure, and satisfaction are directly tied to our worship. In other words, we cannot be truly happy unless we are living lives of worship to God. We spend so much time trying to see how close we can get to sin without actually sinning because we want Jesus and our vices. But it is Jesus alone who can bring the satisfaction we are looking for.
This is why we should not ask questions like: "how far can I go before it is a sin?" Instead we should be asking "how close can I get to Jesus?" I know you've probably heard something like that before, but maybe you haven't heard why that's true and so important to understand. It's not about behavior modification or legalism, it's actually about your joy - your joy is found in holiness and worship, not mindless obedience to rules.
You see, it's not truly worship to obey God out of duty. This is why Jesus said, "If you love me, you will keep my commands" (John 14:15). Our love for Jesus drives us to obey and worship Him and that is where we find joy that lasts. You won't increase your joy by following the rules better, but by loving Jesus more - which actually will help you follow the rules better as well.
At the very same time, it is the very duty of worship that will often drive us to delight in our Savior. I am not in any way suggesting that we should only worship and obey God when we feel the emotion of love for Him. I'm saying that love is a choice and action that will in fact fuel our emotions and ignite our joy in Him; which can only lead to more worship and obedience. This almost exactly how a biblical marriage should work (I guess Paul was on to something when he said marriage is a picture of Christ and the Church).
Tim Keller said, "The sin beneath all other sins is a lack of joy in Christ." I believe He is right. Consider even the original sin of Adam and Eve. They decided they wanted more than God and what He had given them. At some point, they decided that they would find more joy apart from God Himself. In order to find that joy however, they had to step outside of His Law. So the very first sin was, at least in part, driven by a lack of joy in God and a desire to find it elsewhere.
The Psalmist said rightly: "You make known to me the path of life; in your presence there is fullness of joy; at your right hand are pleasures forevermore" (Psalm 16:11). It's all because true joy can only be found in abandoning our pursuit of joy for the pursuit of God. In the end we find exactly what we have been looking for the whole time. Joy is not simply a by-product of worship, but the result and reward of it.