Since the only way to be sure you're not running any malicious code is to only run software written by yourself (and that includes the compiler itself in case you're wondering), it's quite clear any real-world use of computing will carry some amount of risk of running buggy and/or malicious code - so better get used to it.
Utter sophistry - not all software is as trusted as other software. The gpg signed and verified RPMs downloaded from CentOS - trusted. The random browser plugins downloaded from google - not trusted.
Despite not trusting all sources of software, I can still do useful things with a computer without having to have written every line of it myself. This doesn't mean that I "just get used to it" and accept software from any source..