Ikhlaas refers to the capacity of having sincere intentions in both acts of worship (ibadah) dedicated to God and our dealings with others, as we strive to seek God’s pleasure. The present research was primarily conducted to develop a psychometrically sound measure of ikhlaas and establish its construct validity. Using an exploratory sequential mixed methods design, it comprised two studies. Study 1 was conducted in three phases. In Phase 1, an initial set of 17 items for the Ikhlaas Scale (IS) was developed through the thematic analysis of Quranic verses, semi-structured interviews, and focus group discussions. Phase 2 was related to the translation and cross-language validation of scales. Phase 3 involved administering this item pool to a sample of Pakistani Muslim adults (N = 300) and conducting an exploratory factor analysis (EFA) that revealed a two-factor structure (item loading 0.45–0.89) for the 12-item IS, accounting for 43.65% of the variance. The first factor measured ikhlaas in worship (7 items), while the second factor measured ikhlaas in dealings with others (5 items). Ikhlaas had a significant positive correlation with taqwa and significant negative correlations with materialism, providing evidence for the convergent validity of the IS. In Study 2, confirmatory factor analysis (CFA) conducted on a sample of Muslim adults (N = 702) confirmed the 12-item, two-factor structure of the IS observed in the EFA. Ikhlas was positively related to religious commitment and religious emphasis. In the final measurement model, the average variance extracted (AVE) of all constructs (ikhlaas, religious emphasis, and religious commitment) was > 0.50, the values of maximum shared variance (MSV) were lower than those of AVE, and the diagonal values of the square root of the AVE were higher than the intercorrelations. The heterotrait–monotrait correlation ratio (HTMT) ranged from 0.51 to 0.61, which testified to the discriminant validity of IS. Overall, the IS is a robust measure of ikhlaas that needs to be further studied for developing its nomological network across global Muslim populations.
