Shiva Purana
तस्मात्सर्वप्रयत्नेन भक्त्यैव शिवमर्चयेत् ॥ अभुक्तानां क्वचिदपि फलं नास्ति यतस्ततः ॥ ६४ ॥
Hence, by all means, one shall worship Śiva with devotion alone, since non-devotees secure no benefit from anywhere.
english translation
tasmAtsarvaprayatnena bhaktyaiva zivamarcayet ॥ abhuktAnAM kvacidapi phalaM nAsti yatastataH ॥ 64 ॥
hk transliteration by Sanscript