Matthew 5:8, “Blessed are the pure in heart: for they shall see God."

To paraphrase:  Blessed are those whose heart motives are pure, clean, and holy. It is our sincerity of intention and will that is required. This does not mean Christians are perfect in their motives. Our hearts, minds, and consciences have been sickened by sin. Jeremiah 17:9 (ESV), “The heart is deceitful above all things, and desperately sick; who can understand it?” Therefore, Christians need to fight against our sinful tendencies daily.

The good news is Jesus's sacrifice covers our sinful thoughts and actions. 1 John 1:8-9 (ESV), “If we say we have no sin, we deceive ourselves, and the truth is not in us. If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.” So, as we walk with Jesus, striving to obey God's will, and developing a more Christ-like character, God is helping us to cleanse our hearts.

Jesus is also aiding believers to become purer. He teaches and washes us. Ephesians 5:24-27 (ESV), “24 Now as the church submits to Christ,…Christ loved the church and gave himself up for her,  that he might sanctify her, having cleansed her by the washing of water with the word, 27 so that he might present the church to himself in splendor, without spot or wrinkle or any such thing, that she might be holy and without blemish.”

We work diligently to purify ourselves. We follow 2 Peter 1:4-9 because “… if you do this (develop the fruit of the spirit) you will never fall.”  2 Peter 1:10 (RSV). We remember this precious promise, “Beloved, we are God's children now, and what we will be has not yet appeared; but we know that when he appears we shall be like him, because we shall see him as he is. And everyone who thus hopes in him purifies himself as he is pure.” 1 John 3:2-3 (ESV)