it's very tempting to say turing complete language will solve everything, theoretically it's true, in practice it's not the best option, since it will also open up an infinite attack vector, logic is simple, if you have infinite possibilities, you will need to deal with infinite attacks.
On the other hand, here is a great talk presented by Russell O'Oconor https://youtu.be/TGE6jrVmt_I where he explained in more details why turing complete is not a good option, delta 0 formulas might be expressive enough to build secure and useful blockchain language that's verifiable with no halt problem.
Recently a paper called 'Simplicity' published by blockstream that discuss this approach more, this allows safer and verifiable smart contracts.