The world is not set up to support holiness. Indeed, except you can own a private island where you are the only resident, it’s impossible to be holy here. Your eyes will see unholy things and your ears will hear even more unholy things. There’s just too much variety of beings on earth and you can’t escape sin alive. But what role holiness plays in prayer is an important subject for the believer, and I believe it a reason many believers shy away from prayer. Because we know God is holy, the assumption is that you must be holy to approach him in prayer. This simply is not true. He was here as a man and knows this environment very well. Besides, he made this place.
What God looks for is the nature of your heart, the love of God in you. If you have believed in Jesus Christ in truth, he has loaned you his holiness for free, and forever, Amen! The thing you must watch for is willful sinning, whereby you see sin and a heart without love, as a normal way of life. That’s making mockery of God, disregarding him and his commands. He frowns on that, and it will not get you far with him. Yes, you will still be his child, but distant from his special favors when you really need it, in prayer until you repent. The Psalmist prayed this prayer – “Keep your servant from willful sins, may they not rule over me. Then I will be blameless, innocent of great transgression.” (Psalm 19:13 NIV)